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Full text of "73 Magazine (May 1969)"

WORLD'S LARGEST INDEPENDENT HAM MAGAZINE 





SPECIRGIIUUi 



OVER 40 FEATURE ARTICLES 



Quads 

Vees 

160M 

15M 
VHF 
Verticals 
Long Wires 



Matching 
SWR indicator 
Tuning Beams 
Slot Antenna 
Turnstile 
Broadside 
Kite Antenna 



GALAXY SSO TEST 
LICENSE COURSE 

WHO'S WHO 
QRP DX 
RTTY 

ETC., AtCp, ote. 






^m 



NEW Power! 
NEW Features! 

NEW Beauty! 





5 BAND 
SSB 

Mobile or 

Fixed 

Station 



1E^ AND A COMPLETE LINE 

MATCHED ACCES 



HANDSOME 

SORIES! 




"A^.t 



:i^„ 




The New Galaxy 
Wattmeter/ Antenna Selector 



»475.00 



The Powerful New Galaxy 
GT-530 TRANSCEIVER 





M9.95 



The Beautiftil^ Matching 
Galaxy Speaker Console 




Husky, and Handsome! 



You asked for it. ..now it's here! The new GALAXY GT-550 and a com- 
plete line of handsome matching accessories! 

Your suggestions made it possible. We took your ideas— added some 
of our own and went to work. We built in new power, new conveniences — 
such as a 25 kHz calihrator option, and no frequency jump when you switch 
sidebands. Then we hired the best designers in the business to give 
GALAXY a distinctive "New Look"! 

Our new GT-550 has all those great qualities of the famous Galaxy V's 
...and then some! It has new POWER.,. 550 watts SSB, making it the hot- 
test transceiver made! A new single scale VFO Dial makes frequency 
interpolation child's play... the new skirted knobs make tuning and band- 
changing a split-second job . . . and, that slick, king-sized finger-tip tuning 
knob works like a dreaml Compact— only llV4xl2%x6" ! $475 Amateur Net 

P.S. Sounds unbelievable but it's an even HOTTER receiver than 
our previous Galaxy V*s! 
^L Space prevents telling you all about the handsomey matched accessory 
^^^^ line. Write for a free brochure that's loaded with exciting news! 



BaiAXY EuenoHics 



'Pacesetter in AmafeurlCommercial Equipment Design" 
1 South 34th Street • Dept. 73*AA4] • Council Bluffs, Iowa 51501 



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^£JLCa-JLZIlTS3 



73 Magazine #104, May 1969 Contents 

4 Who's Who in Amateyr Radio *., ,.„,.,. ...W8GI 

Cefebrftfes in our rankle 

B Stacked Gamma Matched TurnstrTe .•.••.*,-„.WA9LPC 

About 10 db on 2M, omnldirectionaL 

10 VHF Vacation Special -.»,•,,•,. .*»*,.W2ZRX 

2M slot antenna made out of aluminum foiL 

14 &Unit Attenuator ....„„, WA&SWD 

For calibrating S-meters and antenna gain. 

20 In The Beginning „. .,„,„ „„„., K1 YSD 

Not for serious amateurs or heart patients, 

24 Don't Kill Your Generator.. „ „„„ .„.WtEZT 

Just wound it a little, maybe. 

26 Working DX Without Six Elements K5PAC 

Persistance and sneak mess substituted for power. 

£G I ne SHiorX'vve Atniennaic. ...»•*#,#« •#«*«.it..««««..,»ii«iiii*«v*v_i'>a>>>i-«ii.«jFV J rUw 

10<15-2QM, S6* on a leg., .and it works. 

30 The Little Wonder • ..-..- ,„W52BC 

&0'10M antenna... looks a lot like the Joystick. 

32 Easy Tuning of the Quad.. .W4AZK 

Multi-element quads can be awfully difficult- 

36 The Antennascope— An Effective Tool. ,«.VE3C£A 

It's okay if you know how to use it, 

40 Two on Top....,^..^,......,.,..., W6AJZ 

SOM vertical which tunes both ends of the band. 

42 Measuring Antenna Gain*..p....k#«*...*...»i« ..*«».»..«««««* W2EEY 

You don't just ask around for signal reports. 

46 QRP-A New World To Conquer • .JWBTYP 

Where 1.000 watts is a full gallon. 

48 Report on The Galaxy 550 ,.„„W6AJZ 

Great new transceiver... read all about it. 

52 Feeding & Tuning Three Band Quad „,, ,..WA4VWY 

Boo ml ess quad.., novel approach,,, etc. 

56 To Patch or Not To Patch ..„ .»....,..W5LHG 

Here's the latest news on patching. 

60 Direct Reading SWR Indicator .„,K3WRW 

Tired of switching back and forth? Lazibones. 

62 Asymmetrically Feeding Long Wires...«......p .— W2EEY 

Strange things happen when you move the feed around, 

68 73 Tests the James Research Units., W1 EMV 

And finds them outstanding. ..and mild. 

70 Compressed Vertical for 160.. W6FPD 

If you have room for a 120* tower pass this by. 

72 Class A Transistor Amplifier Design WA5SWD 

Seven steps to total and complete success. Probably, 

74 $4.98 Novice SpeciaL.„-.---..„„ .WA7CSK 

Why ^end more for a nice 15M antenna? Why not? 

77 How To Fly Your Kite.......... EI4R 

Simple 160M antenna for Field Day or expeditions. 

78 In Search of a Better Angle K9YOE 

Angle of radiation is of critical importance. Read. 

84 FSK Exciter................... .W4LLR 

Another bone for the RTTY fiends. 

88 Telephone Beeper ....W6BLZ 

Handy gadget for the new phone patch 1aws» 

82 KW Dummy Load. ..Cheap**.. ..•<«..—>•..«*•**««*»«.•««. •^...••.WBSPTU 
Start using this instead of your antenna. 

Another of his little 10 kw linear amplifiers, almost, 

96 DX From DL Land.... .,...-..„•.,- , ..........,.„...DL4BR 

What it's like over on that end. 

98 Phonetics for the Pileups ...»,».... KN6I J 

How to get your caM letters through the mess, 

100 Extra Class License Course ...» ...Staff 

Part 4 of the Extra Class Study Course. Learn. 

11B E^}nomy Chronometer JAf 9 EDO 

Sonrie ha mi are pretty doggone cheap. 

Another Shortcut for the cheapskate hann* 

122 All Sand Curtain Array.- •.•.,.-. VK4SS 

160-10M and only 112 feet long* 

123 How To Tune A Circuit K5LLI 

Figuring capacitance, and paraHel cspacitsnce, 

130 Mobile Antenna for Vacation Use.....«»......*......«....... WBZWYO 

iSJot much trouble and uvorks slickeydoo. 



Features 


2 


de W2NSD/1 


16 


Armed Force* Day Skeds 


38 


Matching Short Cut 


38 


DX Quiz 


45 


Different TR Switch 


50 


Novice 15M Antenna 


51 


Super SS 


59 


Technology Race 


66 


Beams in Basement 


66 


SWR Bridge Rear Connectori 


73 


Even Better Gamma 


76 


FCC Action 


87 


The First QSL 


93 


Coax Switch 


116 


New Books 


121 


RF Sealing Tape 


127 


SSB Escalator 


128 


New Products 


132 


Letters 


140 


Caveat Emptor 


144 


Propagation Charts 


146 


Advertising Index 



STAFF 

Editors 

Wayne Green W2NSD/ 1 

Kayla Bloom WIEMV 

Advertising 
Bill Beatty 

Production 
Roger Block 
Nellie SUdar 
Tim Garfield 

Composition 

Louise Constant 

Art 

Bill Kellogg 
Bin Marello 

CJrculattnn 
Mary Andreae 
Dorothy Gibson 
Ruth Ring 

Publicatrons 
George Griffith 
John Van Hillo 
Mike Hill 

l^ney 

Doris Stuhlsatz 

Propagation 
John Nelson 

WTW Editor 

Dave Mann K2AGZ 



73 Magazine is published by 73, Inc., 
Peterborough, N.H. 03458. Sub- 
scription rater $12-00 for Three 
years, $6.00 for one year. Second 
Class Postage paid at Peterborough. 
New Hampshu^e, and at additional 
mailing offices. Printed at Pontiac, 
Illinois, U, S, Entire contents copy- 
right 1969 by 73, Inc. Postmasters, 
please send form 3579 to 73 Maga- 
zine, Peterborough, New Hampshire 
03458. 



MAY 1969 



de W2NSD/1 



Wavno Green 



Just where does amateur radio stand to- 
day? And, where is it going? Obscenity on 
our bands. ..disenchantment with the ARRL.,. 
also with the FCC, ••worry about the ITU... the 
Miller 'effect' on DXing,.,home brew dying... 
movements to CB-ize our hobby,.. our empty 
Extra Qass bands—growth of the hobby 
stopped, ..major manufacturers leaving or left 
for CB money.. -terrible QRM on a few bands 
,,*wide open emptiness on others...clubs lan- 
quishing.-.etc. Do we have more problems 
than we can solve? And, who is to solve 
them? 

Let's briefly look at our background and 
then try to see where we are today. 

The beginnings in any field of discovery 
are left to the amateur. The first radio ama- 
teurs were experimenters who built a good 
deal of their own equipment for the fun of it 
and got on the air with spark transmitters 
and fought QRN and, eventually QRM, Ama- 
teurs, naturally, were responsible for a lot of 
the important developments. As radio com- 
munications became a bigger and bigger bus- 
iness the ham bands shrank accordingly and 
more of the developments were made by 
larger companies who could afford the re- 
search engineers and exoensive equipment re- 
quired for the work. 

By the late 20's commercial receivers were 
becoming popular and fewer and fewer ama- 
teurs took the trouble to build their own. 
Most of the amateurs buUt their own trans- 
mitters right up until WWII. This was be- 
cause there were not enough amateurs to 
make commercial production of transmitters 
profitable at the time. 

After the war there were so many surplus 
transmitters available that there was little in- 
centive to go out and buy parts for building 
a new rig. With Command Sets selling for $5 
which, with a little conversion, would give 
100 watts of very stable VFO power on most 
ham bands, one would have to be crazy to 
spend $ 1 00 or so on parts to build the same 
rig. I remember buying a 100 watt Jefferson 



Travis surplus transceiver which covered 160- 
80-40 meters, AM phone and CW, a bimch 
of the Command Sets, SCR-522's galore, 
ARC-4*s, a Meissner Signal Shifter, a BC»312 
and an SX-28.,.all surplus and all of which I 
used for years. The Signal Shifter, with a 
little NBFM modulator I put in, connected to 
a pair of surplus 813*s, let me work the world 
...on all bands! 

About the time surplus began to fade away 
our manufacturers saw that the ham market 
had grown big enough to make it worth while 
to add transmitters to their receiver Unes, 
What ham in his right mind would go out and 
spend $200 for parts to build a rig that has 
no resale value worth mentioning when he 
could buy the same rig commercially for per- 
haps $250? A handful of amateurs continued 
to build their rigs, but they did it for the fun 
of building and had to recognize that econo- 
mically they were in the hole. 

Amateur construction did not die, by any 
means. Thousands of amateurs continued to 
build equipment*.. but now it was VHP gear 
which was not available commercially-.RTTY 
terminal units.,. gadgets. Building projects in 
the ham magazines would often be duplicated 
by hundreds of readers. Probably only about 
25% of the amateurs built equipment at this 
time, compared to the near 100% of the 30's. 

Then came the transistor. Most of the 
older timers didn't even try to accommodate 
to the transistor. They went on for a year or 
two or even three buOding the tube circuits 
published in the magazines and ignored the 
transistors. As time went on fewer and fewer 
of those cartons of old tubes in the closet 
would fit into the new projects being pub- 
lished. Hardly anyone called for an old bath- 
tub capacitor (condenser) anymore. 

The percentage of home construction 
dropped. Most of the radio parts distributors 
went to selling complete equipment and CB 
rigs, leaving the parts jobbing to a handful 
of large mail-order houses. Gone was the day 

fConfinued on page 89) 



73 MAGAZINE 




and electronic equipment 



■UA^MAdBAddfi^AA^AA^^iUAAB^ 












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INTERNATIONAL CATALOG 




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International Crystal Mfg, Co., Inc, 

to North Lee 

Oklahoma City, Okfahoma 73102 



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Rush FREE catalog 



NAME 



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PLEASE PHI NT 



STATE 



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WTio's Who in 



Amateur Radio 



Welis Chapin, W8GI 

2775 Seminole Road 

Ann Arbor, Michigan 48104 



We have celebrities in our ranks. There 
are many illustrious and glamorous names in 
the Call Book. Oddly enough, however, des- 
pite their status in their various fields of en- 
deavor, these well-known persons do not 
constitute an aristocracy within our midst. 
Far from it! For Amateur Radio, unlike 
other forms of activity, exemplifies true 
Democracy. It cuts across class lines with 
complete disregard for wealth, social stand- 
ing, nationality and creed. 

Many of our colleagues possess names 
which are universally recognized, and it is 
high time that we acknowledged their pre- 
sence among us. At a point in time when we 
hear constant warnings that our frequencies 
are in jeopardy, we may help to preserve our 
allocations by generating a program of better 
public relations. It is certain that we can use 
a more positive image. And surely, publiciz- 
ing the names and achievements of our more 
eminent and distinguished hams will tend to 
enhance that image. 

There are hams in medicine, law, show 
business, the clergy, the military, Big Busi- 
ness, Government, foreign royalty, and two 
of us have even run for the highest offices in 
our nation, 

Not because of established protocol, but 
because it seems a likely place to begin, here 



are some hams with the *'Blood Royal" in 
their veins. P. T, Namgyal, King of Sikkim, 
operates from the Palace at Gangtok as 
AC3PT. He has an American wife, who pro- 
bably complains about the unsightly tower 
and beams which disfigure the looks of the 
house, just as ours do. 0E3AH is- Archduke 
Anton von Hapsburg, the Austrian pretender. 
Moulay Hassan, CN8MH, is King of Morocco, 
In Saudi Arabia, where Ibn Saud, who was 
probably the last of the absolute monarchs 
in the world, operated as HZITA, three of 
the Princes hold ham tickets. Crown Prince 
Abdullah is HZl AF, Prince Talal uses the late 
King's call, HZlTA,and Prince Saud ibn Saud 
was HZISS, So much for the blue bloods. 

I wonder how many who have visited that 
famous landmark in New Orleans, Antoine's, 
realize that it is owned and operated by Roy 
Alciatore, W5RU. Roy loves to QSL, and he 
usually sends a commemorative Mardi Gras 
medallion along with his card. 

Many DX'ers are familiar with the call, 
UAILO. Sad to say, this ham is now a Silent 
Key. He was the Soviet Union's intrepid 
Cosmonaut, Yuri Gargarin^ Incidentally, it is 
being rumored that one of our own Astron- 
auts, who is a ham- may operate a rig on a 
forthcoming moon ^not. It is said that the 
operation will be on the 144 MHz band. 



73 MAGAZINE 



Here are several hams who have achieved stature in the entertainment world: 



Arthur Godfrey 


K4LIB 


Tex Beneke 


K0HWY 


Bill Leonard 


W2SKE 


Alvino Rey 


W6UK 


Harry Gumm 


K6MDD 


Mel Shavelson 


W6VLH 


Andy Devine 


WB6RF,R 


Dave Mann 


K2AGZ 


Bob Mersey 


W2TXI 


trnie Lehman 


K6DXK 


Julius Baker 


W21DY 


Paul Weirick 


K6AK 


Jean Shepherd 


K20RS 


Luz Zuluage 


HK6LT 


Pee Wee Hunt 


WIAYA 


Cliff Arquette 


ex W6SGP 


Freeman Gosden 




Bobby Byrne 


WB2JDG 


Wilmer Allison 


W5VV 



While we're on the subject of entertain- 
ment, 8XK, the ham station of Frank Conrad, 
later became known as KDKA- This sta- 
tion in Pittsburgh, was one of the pioneer 
stations tn the crystal set days, and many's 
the hour spent manipulating the old cat's 
whisker, trying to pull in KDKA, back in the 
20's. ReaUy, the broadcasting industry owes 
its very existence to hams, for they laid the 
groundwork and experimented independently 
so that the principles of radio broadcasting 
could become a practicaHty. Prior to their 
work, radio was used solely for the commun- 



Radio & TV personality 
Band leader 

Radio & TV announcer 
Band leader 
Circus clown 
Screen writer, producer 
Famous character actor 
Songwriter of many hits 
Recording producer, conductor 
Film writer (Sound of Music) 
1st Flutist NY Philharmonic 
Arranger (Lawrence Welk) 
Humorist, Radio personality 
Miss Universe 1959 
Famous jazz musician 
Charlie Weaver 
Amos 

Trombone, record exec 
US Davis Cupper 
ication of messages* The concept of broad- 
casting music, sporting events, Presidential 
Inaugurations, and such, was strictly the 
brainchild of hams. 

Incidentally, there are many firms which 
make ham gear whose proprietors hold tick- 
ets. Art CoUins, W0 CXX; Frank Gunther, 
W2ALS; Percy Spencer, WIGBE; Parker 
Gates, W9DZT, and many, many others* 
BUI Halligan, W9AC, founder of the HalU- 
crafter Corporation, was one of the founding 
fathers of our hobby, and deserves special 
mention. 



Here are some outstanding business people who are amateurs: 



Cyril Staud 


K2DQ 


Harry Vickers 


W8HBY 


Herb Sco field 


W8DB1I 


Buzz Reeves 


K2GL 


George Davidson 


K6EI 


E. Henderson (dec'd) 


WIUUY 


Harold Churchill 


W2ZC 


Bill Newcomb 


K2CNX 


Harold Carlson 


W2UNR 


Find ley Carter 


K6GT 


Bob Waters 


WlPRl 


Carl Lindemaiin 


WIMLM 


Bob Ehrlich 


W2NJR 



General Electric has over 1000 hams, and 
there are hundreds at RCA, Westinghouse, 
Bell Telephone and others. Ford Motors has 
a ham club with over 100 active members. 
There are amateurs in all sorts of industrial 
and commercial institutions. Banks, depart- 
ment stores, railroads, shipping companies, 
utilities, airlines, mining and smelting com- 
panies, steel and copper firms, newspapers, 



Vice Pres-j Eastman Kodak 
Pres*, S perry Rand 
Pres*, TMC Systems 
Reeves Sound Studios^ etc. 
Exec. J Standard Oil 
Exec, Sheraton Hotels 
Exec, Time E*ublications 
Insurance Exec. 
Exec, Associated Press 
Director, Stanford Research 
Pres., Waters Mfg. Co* 
Vice Pres., NBC 
Exec, AT&T 

book publishers, advertising agencies, drug 
firms, oil producers; these are just a few cat- 
egories of business where hams may be 

found- 

The clergy is well represented. Father 
Dan Linehan, SJ,, of the Weston Observa- 
tory, WIHWK; Father Tom Aquinas Cox, 
W2CBX, of the International Radio Mission 
Association; Father Chuck Tardiff, 5H3 Jack 



MAY 1969 



a 



Rabbit, and Father Moran, 9N1 Mickey 
Mouse, are some of the more well known 
ones* And there are countless priests, nuns, 
ministers and rabbis, chaplains, and at least 
one Greek Orthodox priest, all yacking away, 
even as you and L 

Many of us remember the sinking ship. 
Flying Enterprise, whose skipper refused to 
leave, even after he had ordered his crew to 
abandon ship. His gallantry made headlines 
all over the world. This was Kurt Carlson, 



W2ZXM, who can often be heard on 20 met- 
ers, operating maritime mobile from the sev- 
en seas. 

The president of Louisiana State Univer- 
sity is John Hunter, W5DTL. WIDDB is 
the reknowned sculptor, Allison Ma comber. 
And, Bill Juhre, the syndicated cartoonist is 
W9IMQ, Ray Blosser, W8DBK, is vice presi- 
dent of a bank in Qeveland, We've got 'em 
all over! 



Politics and the Diplomatic Service are not without hams. Of course, we all have heard of 
K7UGA/K3UIG, Barry Gold water. Some of the less publicized ones are: 



William Porter 
Maurice Bienbaum 
Arm in Meyer 
Dudley Mason 
Bert Delotto 
James Homes 
John Doughten 
Carl Ruh 
Frank Hazelbaker 
John Thompson 
John McCarthy 



K1YPE/XV5 

HC2KX 

0D5XX 

KW6CJ 

W6FGY 

W6REK 

W3LV 

W4TZT 

W7FTP 

W70AZ 

KIEMO 



There have always been many hams in the 
military- Since communications are a vital 
link in the successful maintenance of a pro- 
per military establishment, it would be diffi- 
cult to envision a situation in which there 
were no reasonably close relationship be- 
tween the Defense Department and Amateur 
Radio, In times of crisis, we are expected to 
furnish a pool of experienced communica- 
tions personnel, upon which the military can 
depend. This calls for some degree of liaison. 

Some of the higli ranking officers who 
who hold licenses are: 



Re^r Admiral H. Brut on 
Major Gen. Elmer (Bill) Littell 
Gen. W- W, Watts 
Admiral McCarley 
Admiral Weatherwax 
Major Gen, Shuler 
Gen, J. Smith 
Adj. Gen. Win do m 
Gen. Joe Still well, Jr. 



W4m 

K3BNI 

W4VI 

W6BSH 

W4PDW 

W4KN 

W6RT 

W8GZ 

W4FPE 



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Dep. CM. of Missions in Viet Nam 
Ambassador to Ecuador 
Ambassador to Lebanon 
Governor of Wake Island 
California Legislator 
California Legislator 
Pennsylvania Legislator 
Kentucky Legislator 
Montana Legislator 
Montana Legislator 
Former Comm'r of Finance, Mass. 

The history of Amateur Radio, indeed, 
that of electronics in general, is star-studded 
with many great names, each of which would 
be entitled to an individual article; their con- 
tributions have been so significant. Men like 
De Forest, Col pit ts. Hartley, Meissner, Arm- 
strong and Hazeltine, all hams, have given the 
fruits of their genius for the betterment of all 
humanity. Without the work of these pio- 
neers, many of the marvels which make life 
easy today would not even exist. It is fair 
to say that these men were giants. 

Thanks to the devotion and dedication of 
thousands of radio amateurs, the art of elec- 
tronics has contributed p-eatly to world peace 
and friendship. Nations^ once widely sepa- 
rated from each other^ have been enabled to 
maintain lines of communication and avenues 
of peaceful approach* 

International aspects of ham radio may 
generate further interchange, resulting in an 
atmosphere of genuine amity and good will 
among the nations of the world. It may 
spread out to the general populations, and 
finally reach up to the ruling circles. In this 
way, ham radio has an opportunity to make 
its greatest contribution of alL Hams every- 
where have a justifiable reason to be proud 
of their hobby. There are few hobbies which 
are so capable of contributing to society^ 

..,W8GI 



73 MAGAZINE 



r 




New 500-Watt 5-Bander from NRCI 

You can't buy a more potent package than the new NRCI NCX-500 transceiver. This 
versatile 5bander is packed with the performance extras that give you the sharpest signat 
on the band, plus an enviable collection of QSL's. Check it out! 



500-Watt PEP input on SSB, grid block 

keying on CW and compatible AM 
operation. 

Receive vernier, with tuning range 
greater than ± 3kHz. 

Separate product and AM detect io n. 

Sidetone monitor, plus built-in code 
practice oscillator. 

Fast-attack slow-reteaseAGC in all modes. 



Rugged heavy-duty 6LQ6's. 

Crystal^controlled pre-mtxing with single 
VFO for effective frequency stability, plus 
identical calibration rate on al! bands. 

Crystal lattice filter for high sideband 
suppression on transmit, and rejection of 
adjacent-channel QRM on receive . . • 
plus solid-state balanced modulator for 
*'set and-forget" carrier suppression. 

Universal mobile mount included. 




AC-500 power supply available Great things are happening at NRCI 

NATIONAL RADIO COMPANY, INC. 



fA#0/*f 37 Washington St., Melrose, Mass. 02176 
■"^ *^' 617-662-7700 TWX: 617-665'5032 



© 1969, National Radio Company. Inc. 



International marketing through: Ad Aurierna^ Inc.^ 85 Broad Street, New York^ New York L0004 



MAY 1969 



Ji 





Gamma 



Matched Turnstile 



Glenn H. Chamberlain, WA9LPC 
4822 Prospect Avenue 
Downers Grove, lUinois 60515 



r 



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F 



Having just acquired the desire to operate 
on the higher frequencies, I purchased a con- 
ventional two-meter rig and an eight-element 
commercial yagi antenna. It v/as immediate- 
ly apparent that the local groups were impos- 
sible to copy readily using the highly direc- 
tional antenna- 

In reviewing the material in the usual hand- 
books» the stacked turnstile appeared to be 
the most promising compromise. However, 
the need to insulate the elements from each 
other J and the matching, seemed overly com- 
plicated. 

Why not a gamma match eliminating the 
need for insulators? The elements were cut 
from 3/8 inch aluminum tubing for the cen- 
ter of the band, 146 MHz, Their length 
from the formula for a half wave dipole is 38 
inches- 

With the gamma match the elements could 
be boiled directly together to a common 
boom. Using number 14 wire, the gammas 
were connected 4 inches from the center con- 
nection of the elements running horizontal 
H" above each element towards the center- 
To provide a 90 degree phase shift between 
the elements of each turnstile, use a quarter 
wave section of RG-58AU. The half wave sec- 
tions for 146 MHz, using the 0.66 velocity 
factor, is 26.6 inches for each. The entire an- 
tenna is then fed at the center of the two half 
wave sections with RG-58AU, 

The antenna was hung about four feet off 
the side of the tower at the forty foot level. 
The feedhne at this location is about 75 feet 
long. A 1 5 watt AM transceiver was used for 
the test. The standing wave ratio was L3 at 
144.4 MHz, L2 at 146,0 MHz, and L3 at 
147.6 MHz, 

The band w^as open when the antenna was 
connected. Reception of an Iowa station 
about 145 miles distant from Chicago drop- 
ped one S-unit when shifting from the com- 
mercialeight^lementbeamtothe home brew 
turnstUe- In comparing my signal with this 
station j my signal also fell one S-unit when 
changing from the commercial antenna. If 
the commercial beam lives up to its specifica- 



iTT*" OH 5/» ^ 



BOLTED ABOUT l" 
OFF CENTER 




13.3" OR 
:4>, CeiSfTlH 
gONNECTEO FH 
'ONE GAMMA TO 
THE OTHER' 

CENTfRCON^ 

NECTEDTO 

GAMMA 



CROSS MEMBERS BOLTED TOGETHER 
AT CEMTER INCLUDING SHIELDS FROM 
THRtE CABLE EWDS. 




a d" ALUIMINUM 
-CONNECT OFF CENTER AP^D BOLT 



3. 



TO TRANSMITTER 



Ati CA^LE RG 5SAU 
OR RG eAU 



Fig- 1- Tlie Stacked Gamma Matched 
Turnstile, 

tions of 15.5 dB gain, this means the stacked 
turnstile has about a 10 dB gain on a long 
haul. 

The antenna had excellent transmitting 
gain when using it in local group communica- 
tion. Receiving was not quite as good. How- 
ever^ if more gain is desired, there is no reason 
two or three of these stacked turnstiles could 
not be hung aiound the perimeter of tower> 
each turnstile being fed with half wave sec- 
tions of RG-58AU cable. 

This antenna is simple to build, cheap, 
hght, omni-directional and required no tuning 
after fabrication. At this QTH, we highly 
recommend it for those "local" schedules, 
and on the longer hauls you might be sur- 
prised, 

„,WA9LPC 



p 



8 



73 MAGAZINE 




«a^ 



imHH 



rmance.. . 



«. * * 



^t^t^0^kS 





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mi^ a*Ti scuuK f*& 



S*«CT 



*•*# l*» «. 4 iJ * I *^ t Ji -^f^J^-t*. 






O; '9 






10 




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rvm K mr 



W fc lu. *. (•'iirt;- C T^.AW*< t; 







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■■■ 






RF ENVELOPE CLIPPING delfvers clean, crisp SSB 
^u^^^iN^^ ^oMTi^ ^i^f^ the talk power that no other 

type of speech processing can match, 
None of that mushiness typical of 
audio clipping and compression . . . 
This signal penetrates! 



9 



^o 



HIGH EFFECTIVE POWER OUTPUT , , . 300 watts 
PEP input combined with the high average power con- 
tent of RF'Clipped SSB makes the CX7 sound more 
like a KW . . , or several, when it's followed by a linear 

RUGGED CONDUCTION COOLED FINAL AMPLI- 
FIER has ample reserve power dissipation capability 
to run all day at full rated input . . . 




DUAL-GATE MOSFET FRONT END provides out 
standing sensitivity plus exceptional resistance to 

overload. Toroidal preselector helps achieve superb 

cross-modulation and desensi- 
^^^^^ tizatton immunity; Steep-skirted 
^^IkSRklSK bandpass first IF above 30 MHz 
M^W^^K^trWt ^■. vi^'<^^ excellent IF and image 

M rejection while avoiding "for- 
^ ^^M||f ^ bidden bands" In frequency 
^. zSK^^ik capability of the CX 7. 





IF SHIFT* control lets you move the received signal 

plus or minus 2kHz from nominal within the extremely 

steep-skirted IF filter passband 

to slice away QRM . , . attenuate 

a heterodyne by 50 db without 

affecting a desired signal only 

500 Hz away! 



^l» 



*Pat. Applied For 



Some of the outstanding distributors who can give you the SfGNAL/ONE performance story are 

• Harrison Radio - Farmingdafe^ Jamaica^ and N,Y,C. • Henry Radio - Los Angeles and Anaheim, 
California, Butter, Mo. • Amateur Whotesafe Electronics -Corai Gabfes, F/a. m Amrad Supply, Inc. 
San Francisco • Stellar Industries^ - Ithaca^ New York, 



Write for an illustrated 

brochure describing the 

SIGNAL /ONE Model CX7 

"DEL UXE INTEGRA TED STA TtON 



'it Speaks for Itself" 



ff 




A Division of ECl (An NCR Subsidiary) 
2200 Anvil Street N. 'St. Petersburg, Florida 33710 



The VHP Vacation Special 



TSgt Robert H. Wilder, W2ZRX/4 
Box 23, 693 Radar Sqdn 
Dauphin Island AFSTA 
Dauphin J 5, Alabama 36S28 



For years I have been associated with the 
theory of using a simple whip or wire 
antenna and pumping as much power into it 
as you can to work as far as needed. This, of 
course, is a necessity if high mobility 
required for military communications is to 
be achieved. 

With this background I found that for 
amateur operations this usually didn*t work 
if you want a highly portable, cheap but 
efficient vhf antenna system. 

The whole idea was to build an antenna 
from materials at hand in the average home. 
Using this premise a covey of antennas 
ranging from ground planes, verticals and 
simple beams were constructed out of metal 
coat hangers; coUinears from aluminum 
clothes line and even the TV log periodic 
when re-runs were the only thing available to 
watch. 

The latest, which is discussed here, was 
built out of some aluminum foU I scrounged 
from the XYL. (She is WA2YXE and it sure 
helps when you start taping the foil to the 
walls). 

The ''slot*' antenna in its basic configura- 
tion of a plane surface is not usually used in 
either amateur or commercial applications. 
Commercially the slot anterma has been in 
use for several years, but, as in the case of 
navigational systems such as TVOR, four 
cylindrical slots are rotated electrically to 
obtain an extremely accurate circular radia- 
tion pattern. 

Some basic theory of the slot will be 
needed if a practical antenna is to be buUt. 
The slot can be considered a length of 
shorted open transmission line one-half 
wavelength long, so the standard current, 
voltage and impedance curves apply as seen 
in Fig, 1- 




A'<- 



Fig. 1. Basic slot antenna. 

The simple slot is nothing more than a Vi 
wavelength by ,15 wavelength rectangular 
hole cut in a sheet of metal The width of 
the slot is small at the higher frequencies, 
but with current flowing over the entire 
surface of the sheet (both faces) and not 
restricted to the slot edges, the capture area 
of the antenna is extremely large, 

The interesting point is that if the slot is 
cut vertically to the ground reference (Fig. 
2), the antenna will be horizontally 
polarized and conversely horizontal slots 
(Fig. 3) are vertically polarized due to the 
development of the "E** fields of the 
antenna. 




E'FpELOS- — 




Fig. 2. Horizontal poiarization. 
Fig. 3. Vertical polarization. 

RG-8 or RG-58 coaxial cable can be used 
to feed the plane surface ''slot" antenna 
even though the nominal center terminal 
impedance of a resoL* nt Vi wavelength slot 
in a large metal sheet is in the neighborhood 
of 500 ohms. Feeding the slot with the 50 



10 



73 MAGAZINE 



ohm coaxial cable off center will offer a 
fairfy close impedance match between the 
feed line and the slot. The theoretical dis- 
tance from either en I of the slot is 1/20 
wavelength, but the exact point must be 
found experimentally for each installation as 
surrounding structures offer some change to 
the impedance characteristics. The **Rule- 
of-thumb'' is to start at the 1/20 wavelength 
point and work both ways until an optimum 
match is achieved. 

The aluminum foil "Slot" antenna is the 
ultimate of simpUcity in construction as can 
to be seen from Fig. 4, 

The figures in Columns A & B were 
computed from Length (Inches) = 
5905/Freq (MHz) and will work as is, but 
the figure in Column C must be found thru 
trial and error, I found that the distance 
from the end computed for 1/20 wavelength 
worked better from the middle. 

For the best operation some method of 



r 



— A I *5X} 



8 
( 5X 



L 





ifffOM EITHER END) 



I* 



Fig. 4. The VHF Vacation Special. 65 
sheet of IS*' wide aluminum foil (a), (b) 
using chart 1 for measurements, and a single 
edoe razor b^ade^. cut out center piece and 

discard. 











Distance 


Freq 


A 


6 


C 


from end 


MHz 


Inches 


Inches 


Inches 


1 used. 


144.0 


12.30 


41.00 


4.10 


17.40 


144.5 


12.26 


40.88 


4.09 


17.41 


145,0 


12.23 


40.75 


4.08 


17.42 


145.5 


12.18 


40.60 


4.06 


17.43 


146.0 


12.14 


40-45 


4.05 


17.45 


•147.5 


12.08 


40.29 


4.03 


17.47 


147.0 


12.04 


40.13 


4.01 


17.49 


147.5 


11.99 


39.98 


3.99 


17.51 


148.0 


11.95 


39.83 


3.98 


17.52 


MAY 1969 











bonding the coax to the sheet is necessary, I 
found that transparent tape can be used with 
little or no loss of power transfer if the tape 
is tight over the coax conductor and shield 
where it comes in contact with the sheet. 

After construction of the slot antenna 
you should have something that looks like 
(Fig. 5). 



ALUMthiUM FOIL 

SHEE T WITH Slot 

COAX CENTER 
CONDUCTOR 



WALL 



COAX ShiC LD 




COAX 



FLOOR 



Fig. 5, Complete slot antenna* If mounted 
on a door it can be rotated to cover all dir- 

ections- 

The two major lobes of this antenna will 
be through the slot, perpendicular to the 
plane of the sheet. As seen from the top of 
the antenna (see arrow in Fig, 5) you can 
expect a pattern similar to that shown in 

Fig. 6, 

If this antenna can be mounted on a door 




144.0MC stot antenna, horizontal polarlza 
tion. 



. 



11 



,^ .. .. 



COMFK 






■T^ 



QlriK =^ *'*'' >!-■'" 



illill 





i 


t1?^*?5 


^'«?£ ^ 


'TM« m - 




^HCi[y 




9! 


fiJinil>W*?B f2„^ 





eiRfL iA1*W 



jen - 



r^^:-- H9DL 



^W>K. 



73 

DX 
HAND- 
BOOK 



mm Z^tm *^ "f P 



rriii 




including o 

GIANT 

COUNTRY-ZONE 

WALL MAP 



Wall sized world country-zone map 
QSL design secrets for real results 
World airmail postage rates 
World parcel post and air rates 
World QSL and letter rates 
Record list for WAS, WAC, etc, 
Complete up to date DXCC rules 
DXCC and WTW country lists 
Country worked record list 
WA2 record list 
WAZ count ry-preJRx 
ARRL section map 
Logs — propagation cliarts — 2nd op 
Your own DXpedition information 
Card files — QSL managers^ — contests 
Reciprocal licensing — third party 
Inside top DX secrets 
How to win CW DX contests 
CW DX'ing secrtsts by the master 
80M. the best DX band of aU? 

?uick spotting time chart 
ime, by country around the iivorld 
Breaking the tough QSL'ers 
What value foreign stamps to send 
Latest QSL bureau list 
Great circle maps on four cities. 
Bearing charts on ten U.S. cities 
Special ham map of South America 
Ham map of North America 
Caribbean ham map 
Ham map of Africa with latest calls 
World country-zone map in book 

AT YOUR DISTRIBUTOR OR DIRECT 



I Send cash, check, money order +o 



1 
I 



73 Mognziite, Peter borough, NH 034S8 



Name 



j Add 



ress 



City 



-State „^ ,«„J^ip „. _, 



near the transmillerj rotation of the put tern 
will be possible. It was found that by 
swinging the door 90 degrees signals that 
were a clean 8-9 dropped sharply to below 
S-4. 



LOSE aa 




Sheet op foil 



SLOT 



Loef oz 



TOP VIEW 

Frg. 6. Top view of radfation pattern of the 
slot antenna. 

This antenna has out performed every- 
thing built to date including a ground plane 
at 25 feet above ground and the TV log 
periodic at 50 feet above ground. Reports 
have been exceptional up to 25 miles on the 
143.950 MHz MARS frequency which is 
good on the Mississippi coast. Super regen re- 
ceive such as the **Twoer*' are completely 
quieted at 1 5 miles with less than 5 watts fed 
to I he slot, 

.,.W2ZRX 




«» 



Allow me to tune, Roggs— I need the exer 



cise. 



t* 



12 



73 MAGAZINE 



Now your transmitter can work 

or 6 





Model TC-2 

• Full coverage of 
2 meter band 

#180 watts input 









^M 



m{^ 



00 



Amateur Net 



m 



Model TC-6 

Full coverage of 
6 meter band 

300 watts input 

$25Qoo 

Amateur Net 



FEATURES 

All switching between VHF and normal 

low-frequency operation of the exciter 
and receiver is accomplished by the func- 
tion switch on the front panel 

When used with any Drake exciter, no 
additional power supply is needed. How- 
ever, the converters may be powered by 

an AC-3 or AC-4 power supply when used 
with other exciters. 

The low level drive required is obtainable 
from almost any exciter covering 20 
meters or from the TR-6 (with TC-2), 

Oscillator injection may be obtained from 
the Drake VHF receiving converters. 

Transmitting AGC prevents flat-topping 
and increases talk power. 

Metering is provided for both final am- 
plifier plate current and relative output 
power. 

Built-in antenna relay. 

Provision for controlling linear amplifier 
and/or external coax relay. 

Matches Drake 4-Line in appearance. 



Meters 



nwy-'-xiK--'. 



llll^ssa 



fcZ" j^tJ"^ '■-■'-^ 1 '■_■' I 



•r - _ ^ 1. . ■ L a ■ 






■Mf-'M 









DRAKE 

TRANSMITTING 

CONVERTER 



^? 



.■,'-"«,','t, 



'.•'.•iiK-: 



• -^,Vi>---'!.'i-^ 



TC-2 SPECIFICATIONS 

Frequency Coverage: 143.9-148 MHz. 

Frequency Coverage with TR-6 and SC-2: 143.9-144.5 MHz 
and 144.9-145.5 MHz. 

Modes of Operation: SSB, CW, AM, RTTY; determined by 
exciter, 

Average Distortion Products: The odd order are better than 
25 dB below PEP. 

Input Power: 180 watts on CW or RTTY. 180 watts PEP on 
SSB and AM. 

Output Impedance: Nominal 52 ohms with adjustable out- 
put network (SWR less than 2:1). 

Injection Required: 0.25 V. at 130 and 131 MHz (from SC-2). 

Excitation Required: 0.25 V. at 13.9-18.0 MHz. 

4 Tubes, 4 Transistors, 5 Diodes. 

Size: 5V2" high, UVa" deep, yVa" wide. Weight— 9 lbs. 

TC-6 SPECIFICATIONS 

Frequency Coverage: 49.5-54 MHz. 

Modes of Operation: SSB, CW, AM, and RTTY; determined 

by exciter. 
Average Distortion Products: The odd order are at least 35 

dB below PEP. 
Input Power: 300 watts on CW or RTTY. 300 watts PEP on 

SSB and AM. 
Output Impedance: Nominal 52 ohms with adjustable Pi-L 

network (SWR less than 2:1). 
Injection Required: 0.25 V. at 36.0 and 36.5 MHz (from 

SC-6). 
Excitation Required: 0.25 V. at 13.5-17.5 MHz. 
6 Tubes, 1 Transistor, 4 Diodes. 
Size: 5V2" high, UVb" deep, 7W wide, Weight: 9 lbs. 



At your distributors, or write: Dept. 359 
R. L. DRAKE COMPANY 540 Richard Street, Miamisburg, Ohio 45342 



MAY 1969 



13 




99 



Unit 



Attenuator 



Edward A. Lawrence, WA5SWD/6 
218 Haloid 

Ridgecrest, Calif. 93555 



Since the topic of "'S meters'' is a popular 
one among radio amateurs, a lot of tijne is 
spent describing these devices, usually along 
the lines of how generous or "'Scotch" the 
meters are at the QTH of the parties in the 
QSO. After a few such QSO's, I decided to 
build an attenuator, caMbrated in '*S" units. 
My aim was to attain an accuracy of 1 db or 
better, using 5% Hw resistors and simple 
construction so it would be easy to dupli- 
cate. What I wound up with is very simOar to 
the attenuator described on page 40, Janu- 
ary *67, 73. 

As a sidelight, I started out by calculating 
both **tee" and *'pi" pads, and used **pi" 
because all values of resistance are close to 
standard values, but (especially for high 
attenuation pads) the values for "'tee" pads 
can get quite small; and expensive, 

I figured the values required from the 
tables in the Allied's '* Electronics Data 
Handbook^', page 8, 5th edition. (AlUed 
Radio, 75c, full of good info.) 

Since *^S" units are supposed to be 6 db, I 
figured data for steps of 1,2,4 and 8 times 
that amount, or 6,12,24 and 48 db. With 
these steps, any number from to 15 '*S" 
units of attenuation could be selected. How- 
ever, 8 **S" units proved to be too much for 
one step, as shown by the lowered attenua- 
tion at 30 MHz, due to the Inherent shunt 
capacitance of the resistor used in the series 
leg, plus the stray capacitance of the switch. 
So I removed the 8 **S" unit step and 
installed another 4 "'S" unit step. This allows 
selected steps of attenuation from to I I 
'*S" units. 

Here are the values I calculated, and the 
actual values used, based on 51 ohms. The 
steps are switched in series, as required for 
the desired attenuation. 




Front panef showing the switches for the 
various steps of attenuation. 



Resistance Values for 51 Ohm Attenuator: 




R1 




R2 


"S" units DB 


ideal actual 


ideal actual 


1 6 


154 


150 


38 39 


2 12 


85 


82 


96 100 


4 24 


58 


56 


406 390 


8 48 


51.5 


51 


6400 6800 



After the attenuator was completed, the 
attenuation was measured at 3 kHz and at 30 
MHz, With the test equipment available it 
was possible to measure more accurately at 
30 MHz than at 3 kHz. Below is the data 
from the tests. 

Atten Step Predicted Measured Measured 

"S" units DB atten DB at 3 kHz at 30 MHz 
1 6 6.2 6 6-02 



2 
4 



12 
24 



12.3 
23,3 



1Z2 
24.2 



12.16 
24.05 



8 48 48.5 47.5 39.11 

Now if we want to make an educated guess 
as to how far up we can expect good results, 
say 1 db error out of 24 db, then we can use 
the measured error in the 48 db step to cal- 
culate the capacitance across the series leg, 
and from that calculate the frequency where 
the 1 db error will occur. Go through the 
math if that is how you get your kicks, or 
take my word for it. It comes out to about 
2 pF, And this will cause a reduction of 1 db 
at about 220 MHz. And since the resistor is 



14 



73 MAGAZINE 



F 



NEW one 



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Cable "INTEL" 305 444 6207 Export orders our specialty 



3 



n 



DPOT 

o — o 




Fig, 1. Diagram for one step in the atten- 
uator. 

of a lower value for the smaller steps, they 
should hold their values to even higher fre- 
quencies, but I expect other factors would 
get into the act along the Une somewhere. I 
will state that still works well at 2 meters. 

If you want to get fancy, you can always 
figure the values for 1, 2 and 3 db steps and 
have from to 72 db attenuation in 1 db 
steps. 

Referring to the photos; you can see I 
built my attenuator in a Bud Minibox 
CU-2102-A, 4'* X 2-1/8" X 1-5/8". Four 
steps is the maximum in this size box, unless 
different switches are used. Mine are Cutler- 
Hammer 7592K6. The shielding was made 
from transformer strap, but could be any 
soft copper available. Try a Hobby Shop and 
get the thin sheet that is used for embossing 
if aU else fails. 




llllil — I" '.'VI'" 



Looking inside the attenuator. 

Here are some of the uses an attenuator 
of this type is suited for: 

Checking receiver *'S" meter calibration. 

Attenuating signals to aid in peaking 
receivers and converters. 

Calibrating diode voltmeters for rf meas- 
urements. 

Checking antenna gain. Or gain of that 
outboard rf stage. 

P. S. My "S" meter liesjust as I thought! 

. . . WA5SWD/6 



Armed Forces Day, May 17 

Contacts may be made on CW with WAR 
(Washington) on 4001.5, listening 3.5-3.65; 
4020, hstening 3.65-3.8; 6992.5, listening 
7.0-7.1 ; 7325, Ustening 7. 1-7. 2; 14405, listen- 
ing 14.0-14.2. NSS (Washington will be on 
3385, listening 3.5-3.65; 7301, listening 7.1- 
7.2; 14400, listening 14.0-14.2; 2 1 500, listen- 
ing 21-21.25. NPG (San Francisco) will be 
on 4005, listening 3.5-3.65; 7495, listening 
7.1-7.2; 13975.5, listening 14.0-14.2; 

20954.5, Ustening 21-21.25. AIR (Wash- 
ington) will be on 3397.5, listening 3.5-3,8; 
6997.5, listening 7.0-7.2; 13995, listening 
14.0-14.2; 20994, listening 21-21.1. Times 
are 171400Zto 180245Z. 

SSB contacts may be made with NSS on 
4040, listening 3.8^.0; 7336, Ustening 7.2- 
7.3; 14385, listening 14.2-14.35. NPG will 
be on 4001.5, listening 3.8-4.0; 7301.5, lis- 
tening 7.2-7.3; 14356, Ustening 14.2-14.35; 
21600, Ustening 21,25-21.45. AIR wiU be on 
4025, Ustening 3.8-4.0; 7305, Ustening 7.2- 
7.3; 14397, listening 14.2-14.35. 

RTTY contacts may be made with NSS 
on 401 2.5/3.65-3.8; 7380/7.0-7.2; 13940/1 4- 
14.1. NPG wUl be on 4016.5/3.65-3.8; 
7347.5/7.0-7.2; 13922.5/14-14.1. AIR will 
be on 3347/3.5-3.8; 7315/7.0-7.2 

Watch for a plane flying between Washing- 
ton and Boston on 143.82, listening 144.0- 
145.5 on AM and RTTY. Also one flying be- 
tween Los Angeles and Seattle on 143.7, 
listening on 144-148 AM. Mt. Diablo will 
be on 148.41 on AM/FM/RTTY, tuning 
144-148. 

CW Receiving Contest 

At 180300Z (2300 EDT, 1900 PST) May 
1 7th at 25 wpm, there wUl be a special Armed 
Forces Day message on WAR on 3347, 

6992.5, 14405. On NSS on 3385, 7301, 
14400, 21500. On NPG on 4005, 7495, 
13975.5, 20954.5. On AIR on 3397.5, 
7315, 13995. On A6USA on 6997.5. 

RTTY Receiving Contest 

At 1 80335Z at 60 wpm WAR wiU transmit 
the message on 3347, 6992.5, 14405. NSS 
on 4012.5, 7380, 13940. NPG on 4016.5, 
7347.5, 13922.5. AIR on 3397.5, 7315, 
13995. A6USA on 6997.5. A5USA on 
4025. 

Send entries to Room 5A522, Pentagon, 
Washington, D.C. 20315, before 31 May. 



16 



MAY 1969 



If you're thinking about boning up for a higher- class 
amateur license, why not go after a Commercial License too? 
The exams are similar in many ways-and a commercial 
ticket can bring you rich rewards. 



THINKING about going for your 
Advanced or Extra Class License? 
Then why not kill two birds with 
one stone? Study up on your tech- 
nical principles and fundamentals 
with a CIE home-study course— and 
get a Commercial License too. 

CIE license-preparation courses, 
while they're specifically designed 
to get you a Commercial License, 
give you a thorough understanding 
of the **basics'* common to all elec- 
tronic gear- including your own 
and all other amateur radio rigs. So 
they can be tremendously helpful 
in preparing you for the questions 
youll face in amateur exam Ele- 
ments 4 A and 48, 

This might be reward enough in 
itself. But the fact that these courses 
prepare you for a commercial ticket 
too provides the * 'icing on the 
cake/' 

Advantages of a Commercial 

License 

With such a ticket, you're ideally 
equipped to turn your hobby into a 
richly rewarding career— to ''go pro- 
fessional'' and take advantage of 
the exciting job opportunities in the 
booming world of Electronics, 

You^ might, for example, want to 
get into two*way mobile radio serv- 
icing. In this fast growing field, a 
service contract for a typical sys- 
tem pays an average of about SI 00 
a month. -One licensed technician 
can maintain eight to ten such sys* 
tems— and some men cover as many 
as fifteen. 

And there are many other golden 
opportunities in the aerospace in- 
dustry, electronics manufacturing, 
computer servicing, telephone com- 



panies and plants operated by elec- 
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the work is exciting, and the future 
Is secure. 

The *'door-opener'* to it all— and 
in many cases it*s a legal require- 
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License. For passing the Govern- 
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positive to one and all that you 
really know your Electronics, 

The exam is so tough, as a mat- 
ter of fact, that two of three men 
fail it But if you train with CIE, 
you've little cause to worry. CIE 
training is so effective that 9 out 
of 10 CIE graduates who take the 
exam pass it* 

That's why we can afford to back 
our courses with this iron-clad 
Warranty: upon completing one of 
our FCC courses, you must be able 



to pass the exam and get your Com- 
mercial FCC License— or youll get 
your money back. 

Mail Coupon for Two Free Books 

Want to know more? Send the 
bound -in card for a free copy of our 
school catalog, *'How To Succeed 
In Electronics/* describing oppor- 
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with our special booklet, "How To 
Get A Commercial FCC License." 
If card has been removed, use cou- 
pon below, or send vour name and 
address to CIE, 1776 E. 17th St., 
Cleveland, Ohio 44114. 

ENROLL UNDER NEW G\L BILL 

All CIE courses are available under the 
new GJ. Biff. If you served on active 
duty since January 3L 1955, or are in 
service now, check box on card for GJ. 
Bill information. 




Cleveland Inati^uite of Electronice 

1:776 East 1"7i;M Street. Cleveland, Ohio -4-ai1^ 

1. Your 44-page book ''How To Succeed In Ekctroniis" describing the 

job opportunities in Electronics today and how your courses can pre- 
pare me for them. 

2. Your book "How To Get A Commercial FCC License." 

Name_ 



PLEASE PRrNT 



Address 



City 



Zip 



Slate , 

Q Check here for G.L Bill infornisiriiMi 

Accredited Member National Home Study Council, 
A Leader in Electronics Training. *, Since 1934 



=.Age. 



ST-20 ' 



Q. Whaf s better than getting an 
Advanced or Extra Class License? 

A. Getting a Commercial FCC License 
to go with it. 



MAY 1969 



19 



1 



In the Beginning . 



Bob Manning, Kl YSD 
915 Washington Road 
R O. Box 66 

West Rye, New Hampshire 03891 



Not long ago - 'twas October 3rd, 1968 
to be exact, I was pouring L.S.D, into the 
air conditioner — I had taken an overdose of 
Midol barely 28 days previously and was 
morosely ruminating over the plight of the 
radio amateur, I remember the date very 

welL It was the fifth anniversary of ARRL's 
first Incentive Licensing proposal to the 

Since we were about to *gird our loins' 
and march valiantly back into yesteryear to 
the 'golden' or *good old days' I had just or- 
dered a 1936 Hudson Terraplane. dusted off 
all my old Rudy Valley records, bought up 
enormous quantities of lamp wick trimmers, 
pinned on my Alf Landon and Wilkie but- 
tons and started building a two-holer re- 
plete with quarter moon, corn cobs and 
Sears Roebuck catalogs- 

I was looking forward to going backward 
and seeing horse drawn carriages, apple carts, 
bread lines, WPA workmen and the return of 
spats, bustles and cholera- 
Wit hout warning, I was seized by 7?o/o- 
graphitis' which is similar to ^inspirational 
graphitee/ but occurs outside water closet 
areas: 'tis an uncontrollable urge to write — 
something! — somewhere! I immediately 
seated myself and pounded out an article en- 
titled, "Ipecac Works on Lids" (73 maga- 
zine, November 1968). 

The response to this article was over- 
whelming! The fact that *both* letters were 
written on foolscap with crayon and in 
block letters made little, if any, difference. 
The Editor of 73, upon securing my re- 
lease from the Intensive Care Unit of the 




local Domicile for Dememted Ding-a-Lin^ 
suggested I write more articles of similar ilk- 

In the coming months and subsequent ar- 
ticles, I shall - by drawing on a seemingly 
bottomless pit of banahty — endeavor to 
look at the foibles, follies and idiosyncrasies 
of amateur radio in such a way as to be 
humorous and satirical without being offen- 
sive. 

If I am to be thusly foisted upon you, it 
is only fair that — like in high class books — 
you receive a resume' of my bona fides. 
1. how had I become a ham and 2, what had 
put me on the path of 'holographitis* be- 
sides a case of 'hoof and big mouth' disease 
and a diarrhetic typewriter? 

How had I become a ham? Ah yes, I re- 
member it welL Like most things I do, I did 
it backwards. Most hams become interested 
in amateur radio and then get their Mcense. 
I got my license and only then did I become 
interested in amateur radio. This statement 
requires some explanatory background, 

I spent 9 years in the U.S. Navy as a 
radioman and then, after a short stint with a 
British Thermal Unit (that's a hot one!), I 
transferred into the Air Force (ours). While 
I was in the Navy. 1 was considered an idiot 



20 



73 MAGAZINE 



r 



by those whom I thought were of high intel- 
lect. In the Ail Force, the exact opposite 
was true. To this day 1 haven ^t figured out 
whether lis better to be thought an idiot by 
genuis' or a genius by idiots , - , 

This variance of feelings was not, in reali- 
ty, without basis. For, when I entered the 
Navy, it was with the understanding that I 
would be schooled as a Hospital Corpsman 
and study under the famous Doctor Chicago, 
who was doing experimental research in 
'acne' and 'hickey' transplants. Unfortu- 
nately, the 'powers that be' discovered that 
I was color blind and, in their infinite wis- 
dom , transferred me into Radio/ Electron- 
ics — have you ever seen a color blind person 
trying to decipher the color code on a resis- 
tor? The process, like the mating habits of 
the penguin, is strictly *trial and error' fin- 
cidcntly, the trial and error mating habits of 
the Penguin is probably the reason for that 
creatures universal disease, 'pknobo phobia* 
(fear of backing into cold door knobs) and 
the most likely reason for their Charlie 
Chaplin-like walk and accounts for the fact 
that you never see a Penguin in a crouched 
or bent opcr position.). This deficiency on 
my part led my superiors to look askance at 
my attributes. Combine this with my chub- 
by, pear shaped appearance — which gave me 
the unique distinction of being the only man 
in the history of the U.S. Navy to ever wear 
a Bell Bottomed Shirt! and their feelings be- 
come understandable* 

Of course, the fact that I once suggested 
replacing the old libido controlling saltpeter 
practice with a 'dry ice* treatment did little 
to change their opinion. Instead of surrep- 
titiously inserting saltpeter into the food 
fare, I proposed swallowing small dry ice 
capsules to freeze the prostate gland — thus 
arriving at the desired result without altering 
the taste of the food. Unfortunately, al- 
though the process did work, the side effects 
were nothing short of spectacular! It not 
only accomplished its original purpose, but 
also froze the larynx and the colon. The lat- 
ter action created some extremely embar- 
rassing situations for the user and the former 
action precluded him from calling for assis- 
tance* 

Despite these obvious drawbacks — and 
the fact that I suffered from chronic sea- 
sickness, 1 became an excellent radioman. 
My last official test CW paper was accredited 
with 40 wpm. I must confess, however, 
that the officials simply took my word for 
my own test results. The tests had been 



given during heavy seas and the judges — to 
a man — exhibited a strange reluctance to 
either handle or even look at my paper. 
Possessing the ability to send and receive 
CW at 25 and 35 wpm respectively and hav- 
ing trained on a great variety of electronic 
equipment, it was only natural that, when I 
transferred into the Air Force, that they 
would put me to work in a Teletype tape 
delivery center — where the only electronic 
mechanisms were a moldy coffee urn, a Tuc- 
ker built coke machine and the ever present 
'panic button\ 

Eventually, however, I did end up in 
communications at a USAF MARS station 
where I made my first contact with the ama- 
teur radio fraternity. The Sergeant I worked 
for — call him Sam — held a 'Conditionar 
class license* Now, at that time, 1 knew 
nothmg about the Hcensing structure and 
mistook the disdain shown towards Sam to 
be an aspersion on the type of license in- 
stead of the man. Whenever we held MARS 
meetings, the members flicked ashes in 
Sam's lap, lobbed candy wrappers at his Met- 
recal, accused him of having rubber pockets 
to steal soup and stated that, "if he had a 
brain, he'd be arrested for smuggling trash!" 
Having no special love for Sam and being 
blessed — or cursed -- with a caustic 
tongue — and knowing the disdain in which 
he was held, it was inevitable that we should 
eventually tangle. 

It happened! One day, with Sam 

driving our 5 ton truck and with a burly air- 
man seated between us, Sam managed to 
manually manipulate the controls of the 
truck in such a fashion so as to knock down 
two light standards, remove all the warning 
lights from the rear of the vehicle, open a 
new entry way into the MARS station, scare 
hell out of two pregnant dependents and 
caused the airman to slide, in a kneeling 
position, downward and forward under the 
dashboard where he straddled the drive 
wheel lever with considerable force — leav- 
ing him with a strange falsetto voice that 
may well have given rise to the eventual pop- 
ulanty or uny lim. 

Recognizing an opportunity to insert a 
verbal barb, 1 leaned across the agonized air- 
man and asked, "Hey Sam — you got a 'con- 
ditionaf drivers license too?'* 

There is no ire quite like that of an aggra- 
vated NCO and Sam was no exception. He 
immediately turned apoplectic vermillion, 
let out a 15 minute non repetative string of 
expletives and jammed on the brakes — once 



• 



MAY 1969 



21 



■ 



f 



again doing injury to the already anguished 
airman on the floor who, looking up at us 
with DM0 blazoned across his forehead and, 
in a voice pitched somewhere between Jean- 
nette MacDonald and Yma Sumac said, "fer 
cripesakes! ya dummy! you do that one 
more time . . , my navel's gonna look like a 
chin cleft and I'm gonna be wearing my 
truss for love beads!" 

The final outcome of this incident was 
that Sam and I made a hot headed S5 bet 
that we'd both have General Class tickets 
within 30 days. Even though I managed to 
obtain mine in 28 days, I was unable to 
collect. The Air Force, learning of Sam's 
unique ability as a truck driver, had trans- 
ferred him as an instructor to a heavy equip- 
ment school. There I was— I had a ham 
license and didn't know what to do with it. 

Since that time, I guess I've progressed 
normally through the various stages of 'be- 
ing a ham'— I began thinking up witty 
1 1 meter type phonetics for my call sign, de- 
signed and scrapped hundreds of provoca- 
tive QSL cards, progressed into the short 
purposeless QSO "hi there-Tm Bob— - 
broken old bottles — ur five nine — opps 
chow call - c u 1" then gravitated into the 
public service field where I was prepared to 
battle my way through wind, rain, snow, 
sleet, hurricanes, typhoons, hippie uprisings, 
draft card burnings and other similar disas- 
ters to deliver the vital message thereby sav- 
ing countless lives and millions of dollars and 
be awarded the 'purple clavicle' with 'oat- 
meal clusters/ I then took up the contest 
type operation— - **yeah, let's see - if I 
multiply my input power by the number of 
stations, add 5,000 for delivering a confirma- 
tion to the SCM, divide by the temperature, 
subtract 10% for being an appliance opera- 
tor, add 127 points for having read the CD 
bulletin, figure the logarithmic value of pi R 
square (pie are square???? NO! pi are 
round -fig newtons are square) ah..,ta hell 

with it ril cheat. I then settled down 

to appreciating and happily indul^ng in all 
areas and, to paraphrase Will Rogers, "I 
never met a ham I didn't like!" — Eventu- 
aUy, I reached the epitome of all hams„.. 
writing sarcastic letters to ARRL, 

This covers HOW I became a ham*.- 
now, how had I sunk to the depths of satiri- 
cal writings?? 

(International Business and newly formed 
countries want our frequencies, zoning laws 
restrict antenna heights, neighbors ogle us 
uneasily with awe - or fear - as if they ex- 



pected us to mumble some voodoo chant, do 
two back flips and an arabesque, snip a lock 
of hair, sprinkle them with dried octupi eyes 
or dandruff and transform either them or 
ourselves into a 'fried egg sandwich*. TV 
viewers assail us for supposedly screwing up 
their twenty-one year old $37 Japanese TV 
set with the bamboo antenna and, on at least 
one occasion, hams became the topic of con- 
troversy in - of all places - an advice to the 

lovelorn column, our Mothers think we're 
gonna blow up the world - or at the very 
least — the house and our wives wish we'd 
forsake amateur radio for more sensible 
practices like *bulb snatching* or *sky diving' 
or become peeping toms, or winos or study 
the abnormal sex life of the African Ant- 
eater J 

Being a student of Zen, ExtrateniaUsm 
and intensely adroit at deep analytical in- 
trospective soul searching — which, literally 
translated, means "I goof off a lot!" — I 
have given considerable thought to this 
status. I have concluded that objective hu- 
mor — satirical, distorted or prismatic is 
about the only thing that keeps me fro^^i 
running, stark naked, out of the house 
attacking the first AT&T truck 1 see and 
grabbing my neighbor by the throat, stand- 
ing him on tippy toe and driving him into 
the ground with the motor end of a sump 
pump. 

There are, of course, other alternatives 
that a ham may use as a relief valve. Among 
them is the process (which is becoming more 
and more popular) of submitting random 
proposals to the F.C.C. 

I know of one radio amateur whose de- 
mented half brother J Alf, submitted a pro- 
posal within the past week, Alf, being the 
offspring of a neurotic and psychotic (those 
mixed marriages never seem to work out) 
and as an impartial outsider has rather an 
objective view. He submitted what, in the 
light of some of the more recent events, 
seems to be a palatable system for future 
Incentive Licensing. 

Alfs suggestion is that all amateurs be 
immediately reduced to Novice class and 
issued new licenses combined with a fixed 
amount of marbles secreted in a cummer- 
bund, (choice of colors — marbles and 
cummerbund — is optional). As the opera- 
tor operates, he must assume anatomically 
impossible positions — like standing on his 
head with one foot stuck out the nearest 
window - a G,L can may be fastened 6'6" 
above the floor as an effective substitute — 



22 



73 MAGAZINE 



(SometimeSj when I make like an SWL, Fm 
not absolutely sure that this procedure is not 
already in effect) -In this way, the operator 
must manage to loosen the marbles from the 
cummerbund. His operating privileges will 
be inversely proportional to his supply of 
marbles. This will continue until he reaches 
the pinnacle; i.e., the highest grade of license 
and the loss of all his marbles'! Note,..Alf 
submitted an addenda suggesting new classes 
of license- —I don*t know them all, but 
they run something like this: (a) the 
Dummy class (b) Novice (c) Apprentice 
(d) Mediocre (e) Mundane (f) Technician 
(g) Adequate (h) Advanced (i) Improving 
(j) Extra (k) 7^2= +-^""^+=3 2 g^d the 
(1) Whoopee class... 

One item I feel I should inject to round 
out my resume' is the fact that I am quite 
vain. Besides being large of girth and tired 
of fun being poked at my expanse, I was 
once totally bald. 

Because of thiit hairless state I paid a 
thousand dollars for a complete 'FolHcle 
Graft*. (The operation, for the uninformed, 
is the transplanting of hair and roots from a 
volunteer donor to the top of the head of 
the recipient). 

Regretably, in this case, the pafter used 
the hair from the hind leg of a German Shep- 
aid and, since the operation^ Tve fallen in 
love with a State Trooper, have a constant 
craving for ALPO, my backyard is pock- 
marked from my inept attempts at burying 
bones, I can't stop chasing cars and every 
time I pass a fixe hydrant, the whole head of 
hair snaps straight up! 

I hope you will find some enjoyment in 
the articles. Even though I once thought 
Verbiage' was verbal garbage and *sagacity* 
implied some physical malformation, writing 
is not a new thing with me, I am the author 
of one article entitled, ** Where Are The 
Men?" it dealt with the poignant question 
'where is MR. PAUL, UNCLE JEMIMA and 
WHISTLERS FATHER?? - I then wrote a 
ditty titled, " on the Range" and, 

finally, I am putting together an amateur 
radio study book to be called, '^'VE UPPED 
MY OPERATING PRIVILEGES . . 
NOW .UPYOURSl!!!!'' 



i * * 4 



Friendliness and Courtesy are contagious . 
start an epidemic (Kl YSD) 



Kill ignition noise 

and other strong impulses 

wfth a 

NOISE 

BLANKER 
KIT for 

TR-3 or TR-4 




the usual noise clippers or I i miters, the 
34'NB is an advanced noise blanker which actually 
mutes the receiver for the duration of the noise 
pulse- Between noise pulses, full receiver gain is 
restored, fThe receiver AGC is affected only by the 
desired signal strength, not by the noise at the an- 
tenna.) Low level signals masked by noise impulses 
without the noise blanker can be copied when the 
blanker is used. The 34-NB is a must for the mo- 
bile operator. 

HOW IT WORKS , . . 

A noiseless electronic series switch is inserted at 
the output of the receiver mixer This switch is 
operated by the output of a special receiving cir- 
cuit which is tuned to the 9 MHz IF with bandwidth 
of 10 kHz, The switch opens for noise impulses but 
closes to allow the signal to pass* 

The kit consists of these main parts: 9-NB board 
(composed of 17 transistors, 4 diodes and circuitry), 
NBK board, capacitor assembly, switch assembly* 
lever knob, and miscellaneous hardware. 

Installation of the kit is about a two hour job for 
the competent technician only, requiring the usual 
hand tools, plus soldering iron and electric drill. 
Factory installation, $15 plus shipping. 



Model 34-NB 



si29»" 



Amateur Net 



At your distributor or write to 

R. L. DRAKE COMPANY 

Dept. 359, 540 Richard St., Miamisburg, Ohio 45342 



MAY 1969 



23 




Dont Kill Your Generator! 



Jim Ashe, WIEZT 



Going to filter out that noise from your 
car generator so that you can better eiyoy 
your mobile rig? Careful, or you may kill 
your generator, too, It*s been known to 
happen. 

Since generators put out dc, it seems 
reasonable that a little old capacitor (or a 
little new one) across the output shouldn*t 
hurt anything. But it's a fact the output is 
something more than pure dc, or you would 
not be thinking about filter capacitors. Now, 
when you put a capacitor across the output 
you are shorting all that hash, noise, and ac 
that the generator makes, straight through to 
ground. Are you sure you want to do that? 
See Fig. 1. 

All dc generators are really ac generators. 
You don't see the ac because it's rectified at 
the commutator But the commutator 
doesn't do a perfect job, and there is some 
sparking there too, so that there is a lot of 
noise power available at the generator ter- 
minals. 

In normal generator operation most of 



this power is dissipated in the car's electrical 
circuit, which has a fairly high resistance 
compared to the generator resistance. But 
when you put that capacitor across the 
generator's output, while the dc is not 
affected, all that noise power is now disr 
sipated inside the generator — right in the 
armature, as illustrated in Fig- 2. If the 
generator is working hard anyway, perhaps 
during mobile operation, the increased dis- 
sipation may be enough to push it over the 
edge. Result: you buy a new generator 
armature. 

But it's not hard to avoid that trouble^ if 
a filter capacitor is needed. What if you add 
a small resistor in series with the capacitor? 
See Fig. 3. Now the ac is still provided with 
the relatively easy route across the generator 
terminals^ but less power is dissipated since 
circuit resistance in increased, and most of 
the power goes into the outside resistor 
where it does no harm. You get your 
filtering, and the generator survives. Try it 
this way, next time! 



n 



©A 



-VSft( 

AC PART 

P DC 



RESISTANCE 
OF CAR 



_v_l_^vJlT_ J 



i 



1 1 



i 



-vw- 



©AC PART 
OF DC 
^ENEBATOft 



GE^ERATOI? 
EQUIVALENT 
CIRCUIT 



JIT J 



Fig, 1. Equivalent circuit at ac of an auto- 
mobile generator instaHation. Resistance of 
car wiring is probabty larger than that of gen* 
era tor by a factor of 2 to 5, 

Fig. 2. [f the car generator terminals are by- 
passed with a good capacttor, they are short- 
ed so far as ac frequencies and noise are con- 
cerned. With reduced resistance greater cur- 
rents flow, and the ac energy dissipated In 
the armature is several times greater than 



B'^PASS CAPAClTOf^ \S NEAfiLT 
INVISIBLE AT AC SO THAT 
CIRCUIT LOOKS LIKE A SHORT 



FEW 0HM?5 
SEVERAL l^ATTS 







>-*-^ AC PAR'' 
f\/J OP DC 




GE^EPAtOff 

EQUlVALCftJT 
CIRCUIT 



[cir cuit 



under normal conditions. At heavy generat- 
or loads the armature may deteriorate rapid- 
ly; or be destroyed. 

Fig. 3. The simple solution. A small resistor 
added in series with the capacitor reduces 
currents and carries much of the ac dlssipa- 
tfon outside the armature, A few ohms 
should be appropriate, and checks may be 
made by temperature observation or direct 
measurement of armature noise and ac cur- 
rents. 



24 



73 MAGAZINE 




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"World's Largest Distributor of Amateur Radio Equipment" 



•I 



Working DX Without 
Six Elements 



Joseph E. Taylor, K5PAC 

6 Evergreen Court 

Little Rock, Arkansas 72207 



Obviously, you won*t work as much as 
often as the fellow on top of Crow Mountain 
with six elements, wide space, on a 100-foot 
tower and a 2 KW rig. 

But you and I have already learned to 
adjust to that fact of life in our every day 
competition with the **big sigs". 

The point is — you can work a surprising 
amount of DX of aU sorts with Q5 QSO's if 
you go at it right- 
Many American hams do not venture into 
the DX portions of the bands because they 
feel that they are not well enough equipped 
to work any DX- It ain*t necessarily so! 

So you have only 90 watts and no beam 
and very little chance of ijiiproving 
either — you can still work DX and enjoy it. 

Maybe we ought to ask, ''what we mean 
by DX", since not everyone means the same 
thing. 

Old Charlie on the mountain has nearly 
300 countries confirmed now. To him DX is 
another new country. "So what*s another 
MP4 if you already have cards from each one 
that counts?" 

But to most of us DX is that unique 
satisfaction that is associated with calling a 
fellow ham in another country, whether 
3,000 miles away or 10,000 miles around 
the globe, and hearing him come back with 
that sweet sound that is our own personal 
private call! And the thrill is apt to be all the 
greater if we are operating with what we 
know to be less than the ultimate in equip- 
ment. A VQ9 on a beam or a quad is 
satisfying to be sure, but on a dipole there is 
an added dimension to the eAloyment, 

By this 1 am not advocating that you use 
anything less than the best combination of 
equipment and antenna you can muster. The 
six element beam is wonderful if you can 
swing it, but my point is, you aren't out of 
the running if you can't. 

A word needs to be said about what is 
meant by "working" DX too. For some 
fellows it is an exchange of RST, QTH and 
73's- For others it involves a greater degree 



of getting acquainted as person with person. 

Where you will want to find your own 

maximum satsifaction is up to you alone. 

Admittedly, it is harder to maintain a DX 

contact than it is to get one. So your 

percentages go down as your time in QSO 

goes up. In effect each of us works out his 

own pattern here, 

CW or fone? Again we have to look at 

plain facts. Your chances with lower power 
and/or simpler antenna systems are better 
on CW than on fone. A good receiver can 
dig out and render copyable an extremely 
weak CW signal that would be hopelessly 
buried on SSB, let alone AM. 

So, if you can do so enjoy ably, you will 
have improved chances of success in CW 
operating. Don't be overly worried if your 
CW isn*t perfect and your speed is down* DX 
operators are among the world's best at 
matching speeds. You will find fast ones and 
slow ones and very nearly all of them are 
patient, so don't chicken out on this score. 
O* K-, so you are ready to try — now for 
some concrete suggestions which will im- 
prove your chances of success. 

L Check your rig thoroughly. The fact 
that your power is limited doesn't 
mean your efficiency needs to be. 
A weak driver tube may not make 
much difference in rag-chewing in the 
75 meter net. It may lose you many 
contacts in DX operation. Try to make 
sure your transmitter is at 100% peak 
of efficiency. Make sure your signal is 
clean and well keyed. Whatever your 
final power rating, you don't need to 
lose any unnecessarily. 
2. Go over your receiver with the same 
kind of thoroughness. Any tubes that 
even leave you in doubt about their 
condition should be replaced. More 
contacts are lost because of inadequacy 
in receivers than in transmitters. 
If your receiver could profit by the 
added gain and the improved signal- 
to-noise ratio of one of the newer 



26 



73 MAGAZINE 



preselectors^ it is a fine investment. 
If your major problem is lack of 
selectivity, you may receive a good 
deal of help from a Q multiplier. 
If your receiver is not stable it can be 
fatal in DX work. The inclusion of VR 
circuits or some approach to main- 
taining a fairly constant temperature in 
the receiver may help. Separate 
switching which leaves the heaters on 
at all times is a simple approach to this, 

3. Give your antenna system a chance to 
do its best. Make sure it is the best you 
can arrange for a given DX band. 

If the system is not rotatable, try to 
orient it toward your favored direction 
(s). For example, in the central United 
States a dipole oriented NW/SE will 
favor both Europe and Australia, The 
direction of a dipole won't matter 
tremendously, but take whatever ad- 
vantage you can get. 
Remember that the longer your wire, 
assuming it and the line are tuned, the 
better. 

Make sure your feed line is the best 
you can get. Coax may be your easiest 
approach, but compared to open wire 
line it is not as efficient, 
A tuner is not a necessity, especially if 
you use coax, but it wiU more than 
repay you for your effort and cost in 
building or securing one, 

4. Listen — Listen - Listen, Spend hours 
on the bands you are interested in just 
listening* See what bands are open 
when, and to what parts of the world. 
Find out what parts of the DX bands 
will likely be best for you. 

For instance, you may find less 
crowding around 14,075 than around 
14,010. For a signal which has its 
limitations you may do better there 
even though you hear more DX on the 
lower frequency. 

5. When you are going to call a DX 
station who is calling CQ, be ready to 
call the instant he signs. If you drag 
your foot and hear another station 
calling him you probably won*t call at 
alL Assume that the same will be true 
of others. Get in fast. 

Don't call too long. After repeating his 
call twice and your own twice, break 
and see if he heard you. If he isn*t 
answering, try two more of each. This 
is much better than four repetitions to 
begin with. 



6. Calling CQDX, Don't be afraid to do it 
but don't overdo it. Remember your 
signal needs an opening more than 
repetition. Try to find a little gap 
between signals. Call QRZ once and 
sign your call. If there is no response 
caU CQDX twice and your call twice 
and K, No more. 

No fancy stuff - no **AR-K'' — no 
"DX pse KKK", In general the DX 
boys are good operators and they will 
respond to good practice on your part. 

7. Answering, When you get a response 
keep your first transmission very 
short. , . - perhaps , . . , 

XY9AA De K5PAC - R - GM OM ES 
TKS CALL UR RST 559 - 559 QTH 
LITTLE ROCK ARK - NAME 
JOE - HW - XY9 AA DE K5PAC - K 
There is Little point m repeating what 
he got the first time, so unless his 
signal is very weak, keep your repeti- 
tions to a minimum. He will want his 
report, your QTH and your name. The 
rest can come in later transmissions. 
Get your first round completed, then 
get acquainted, if conditions permit, 
and your friend wants to. If he wants a 
short QSO, fine, keep it short. Your 
last transmission can be friendly with- 
out wishing *'73's, 88\ gud luck, best 
DX, and gud health" to each member 
of his family individually. 

8. QSL'ing — If either of you really wants 
a QSL then be prompt about it. If not, 
"pse QSL** is not an essential part of a 
QSO. He won't have his feelings hurt if 
you don't ask him for one. If you 
actually want it, O. K. If not, why put 
him to the trouble and expense? 

This article is written to convince the 
ham - maybe you, if you've read this 
far - that fun can be had in the DX aspect 
of our hobby even without kilowatts and 
beams. 

This is not speculation nor theory. In the 
past we have had quads and beams and I 
thoroughly believe in them. But in our 
present QTH the very best I could come up 
with was a 100 foot long dipole fed with 
open line into a home brew tuner. The rig 
runs about 180 watts CW, 

Frankly, I've had a ball working DX on 
15 and 20 meter CW, Why not crank up 
your rig, oil up the key and join me some 
day soon? 

. . . K5PAC 



MAY 1969 



27 



The Short -Vee Antenna 



OMHl f^ADIATlON 
miMOR LOBES) 




MAJCIMUM 
^- DIRECTION 

(MAJOR LOfiEl 



Fig. 1- The Short-Vee Antenna. 

The short-vee antenna is an effective fix- 
ed-position antenna because of its reasonably 
omnidirectional pattern plus a broad direc- 
tional characteristic in one direction. A sim- 
ple definition for a short-vee antenna would 
be a vee antenna with a leg length of no 
greater than 100 feet or no greater than IVi 
wavelengths, whichever is the shorter. Angle 
between the two leg wires would fall be- 
tween 60 and 100 degrees, Fig. I. If the 
legs are dimensioned and trimmed carefully, 
such an antenna requires no tuner and per- 
mits direct feed to the coaxial line between 
antenna and transmitter. 

The short horizontal vee antenna should 
be made resonant on the desired bands. Do 
so by making certain the legs are an odd 
multiple of an electrical quarter wavelength. 
Equations for deter mining odd quarter wave- 
lengths are: 

1 /4 Wavelength = 246/f ^^ 
3/4 Wavelength = 738/f,^^^ 
5/4 Wavelength = 1230/fj„^ 
7/4 Wavelength = 1722/f^^ 
9/4 Wavelength = 22\Ajf^^ 

The practical electrical quarter wave- 
length of the leg is somewhat shorter than 
the above formula values. In most instances 
for a short horizontal vee mounted at least 
30 feet above ground, the shortening is ap- 
proximately 6%, It is advisable to cut the 
legs long and then cut back slowly to the de- 
sired frequency using an antenna noise 
bridge or swr meter. When usine an swr 



Edward M. Noli, W3FQJ 
351 Limekiin Pike 
Chulfontf Pennsylvania 18914 



meter it is essential that the meter be placed 
a whole multiple of an electrical half wave- 
length from the point where the transntt?;- 
sion line is connected to the antenna, 

Multi'Band Relations 

An interesting relationship exists among 
the odd quarter-wavelength dimensions for 
various amateur bands. For example the leg 
length for 5/4 wavelength operation on 15 
and 7/4 wavelength operation on 1 is ap- 
proximately the same. Thus a compromise 
leg length can be determined that permits 
optimum operation on both bands. Fig. 2. 
Furthermore an additional leg can be added 
in conical fashion to obtain an odd quarter 
wavelength operation on still another band. 



UAKE L^NE 
WHOLE MULTlPl^t 
OF X/Z 



56> 




MAX 

RAOIAtlOli 



COAJt 
LIME 
TO S€T 



Fig. 2. The 10-15 ShortVee. 

Matching is helped by using a compro- 
mise length of transmission line which is a 
whole multiple of an electrical half wave- 
length on each band. In so doing the anten- 
na resistance' is reflected to the transmitter 
with little or no reactance. Thus the SWR 
ratio can be kept below 1.8 to 1 without any 
tuner at antenna or transmitter. This ex- 
pedient permits fast band changes. 

10-15-20 Short Horizontal Vee 

Still another advantage of the short vee 
antenna is its limited space requirement. A 
practical version of this antenna style is 



28 



73 MAGAZfNE 



F 




COAK 
TO SET 



Fig. 3- The 10-15-20 Short-Vee. 



u 



given in Fig. 3, It serves as a fine antenna on 
10-15-20 meter sideband- One pair of legs is 
cut to 56\ In so doing resonance is estab- 
lished on both the 10 and 15 meter bands. 
The second pair of legs is cut somewhat 
shorter to 5r2'', operating as a 3/4 wave- 
length resonant leg on 20 meters. 

The two pairs of legs are brought together 
at the apex and connect to the coaxial trans- 
mission line. The legs fan out from this 
point in conical fashion. Fig. 3, and have a 
separation of approximately 10 feet at the 
far end. 

The apex angle was made 80*^, The total 
length of transmission line from antenna to 
transmitter can be made any whole multiple 
of 45 feet. (The 45-foot figure takes into 
consideration optimum operation on the 
three bands and the velocity factor of 0.66-) 

A line that bisects the small angle of the 
vee is the direction of maximum radiation. 
For the short vee antenna it is quite a broad 
beam. At the same time there are additional 
lobes that provide omnidirectional radiation 
as well- Thus the antenna support positions 
can be selected to obtain maximum radia- 
tion in some preferred direction at the same 
time you can obtain acceptable aU-direction 
radiation as weU- It is not a high gain anten- 
na but does give you that extra boost in 
some preferred direction. 

Along the east coast such an antenna 
could be erected with its maximum direction 
south toward South America. At the same 
time it would provide good omnidirectional 
stateside coverage. If you have a WAS need, 
the maximum direction can be toward the 
west. At the same time you would have 
good north and south coverage. You may 
wish to beam it toward Europe, always 
ready for good openings. At the same time 
you have good stateside coverage, viaKni 



WHAT IS 

THE BEST 

ANTENNA 

HEIGHT 

FOR DX'ING! 

70 feet 
(for 20-15-IOM) 



WHAT IS 

THE BEST 

WAY TO 

GET THERE! 

The 

HEIGHTS 

Aluminum Tower 
*so light you can 
put it up all by 
yourself! No 
climbing, no fin 
poles, no heart 
attacks, 

*A 64 foot tower 

weighs only 140^ 

hinged base 
' fits any rotor 
• costs under 
$350 
no painting 
' no rusting 
doesn't depreci^ 
ate like steeL 



SEE YOUR LOCAL DISTRIBUTOR 

OR WRrTE 
FOR COMPLETE INFOKMATION 



/ 



i 



^f 



sif 



W 



A 



/ 



HEIGHTS 

MANUFACTURING CO 

422& MAYBURY GRAND 
DETROIT. MICHIGAN 

Area Code 48208 



MAY 1969 



29 




The Little Wonde 



r 



Eddy Shell W5ZBC 
1209 Holiday Place 
Bossier City, Louisiana 71010 



- 7' 5" 



M 



Every new QTH for the typical ham brings 
its own antenna problems. Returning to col- 
lege to pursue additional graduate studies 
brought the age-old problem of how could I 
affix an antenna to a college dorm and not 
come under the watchful eye of the co Liege 
authorities? The *" Little Wonder'" and an 
antenna tuner was the answer to my prob- 
iem. 

The basic idea came from an AFMARS 
antenna presently being used by some of the 
Texas members. This antenna is a normal 
40-meter dipole with a coil at each end. The 
coil consists of 197 turns of No, 12 nyclad 
wire» close wound on a one-inch stock. It is 
tuned with a 4 8 -inch pigtail which tunes 
331 1 kHz with a 1:1 SWR, with the ability 
to have a full-size 40-meter dipole for 7305 
and the amateur use as welL (1 inch equals 
50 kHz on the pigtail.) 

The *'Littie Wonder" gets its name from 
the fact that it is a little wonder that the 
"Little Wonder" works* My first contact on 
40 meters was a W3 in Pennsylvania, with a 
barefoot KWM2 at ten o'clock on a Saturday 
night and with the "Little Wonder" leaning 
against a wall in the kitchen location of my 
"ham shack/' 

Construction is simple and all parts can be 
purchased locally: 

1 3/4" hard drawn copper tubing 31V^" 
(junk yard, Sears, etc.) 

1 3/4'* hard drawn copper tubing 43 3/4*' 
(junk yard, etc.) 

4 6/32 r' brass bolts and nuts 

1 36" oak dowel rod (fir will work, but 
oak is stronger) 

1 roll of plastic tape 

1 55 feet of No. 12 nyclad wire (motor 
rewinding shop) 

1 single-wire feedline to run from Little 
Wonder to antenna tuner.. J used 8', 33', and 
59-' (when it comes into the room it could be 
hot with r/, so use a rubber or plastic coat- 
ing on this section). I have found the 59' 
to work best with the Little Wonder about 
35' up on top of a TV mast; however, at 
school the Little Wonder sat on the window 
ledge -so who knows? 

2 3/4" bar stool rubber feet 

I 24 "xl" plastic water pipe to cover coil 
after assembly 




OR VIKING MATCH BDX 



5/4" OOWEL 



3/4" TV MAlT TO HOLD 
LITTLE WOHDER IN 
THf Am 



The Little Wonder 

How to construct: Drill a small hole in 
the wooden dowel 8'* from one end. Twelve 
inches of No. 12 nyclad wire is pushed 
through the small hole. One person holds the 
55 feet of No. 12 tight, and the second person 
starts turning the dowel rod until 197 turns 
have been made. A second hole is then drilled, 
and the other end of the No. 12 wire is put 
in this hole. Friction and the bend of the 
wire holds the coil in place. The dowel-coil 
assembly is pushed into one end of the 
43 3/4" tubing, and the other end of the coil 
is pushed into one end of the 3 1 3/4" tubing. 
A 6/32 hole is drilled through the tubing and 
dowel and a 6/32 bolt makes a mechanical 
connection of the tubing to the pigtail of the 
con. A third hole is drilled opposite the coU 
in the end of the long tubing, one inch from 
the end. A 6/32 bolt is placed in this hole 
for the single-wire feeder to be attached. The 
over-all length of the Little Wonder is 1'5'\ 
Rubber bar-stool feet are then placed over 
each end of the Little Wonder to keep out 
the weather, and the coil section is taped for 
the same reason. Attach your feedhne and 
work the world. 

How to tune the *'Little Wonder'': The 
best method of tuning the rig is to tune the 
unit into a 50-ohm load and then connect the 
antenna tuner, (Do not tune the rig.) The 
antenna tuner is tuned for 1 :1 SWR. (A Vi- 
king Match Box will work finei or make your 

own.) 

How does it work? I am on the air with a 

lone KWM2 from 331 1 kHz to 28 MHz. and 

without it Td be QRT for the nine-month 

period. Trust you will be on the air soon with 

your own **Uttle Wonder/' .,.W5ZBC 



30 



73 MAGAZINE 







HAM/SWL 

ss»/cw 

Get more receiver than you paj for: 11 front panel controls, 12* i" slide-rule dial in five colors, 
conlinuoLis coverage from 535 KHz to 30 MHz including illuminated electrical bandsprend for 
100-10 meters [ham and CB), separate logging scale, sensiti\'ily good to 0.5mV al 30 MHz. Standard 
AM recepfioii, a product detector for SSB CW. fast and slow AVC. variable pitch BFO. cascade 
RF slaj^e, noise limiting in both the IF and audio stages, Zener stabilized so usual warm-up drift 
is virtually absenL OTL audio, illuminated *S" meter, built-in monitor speaker plus front panel 
jack for external (optional) matching speaker. Uses ovar 30 semicnndLrf.lors — no tubes, no 
niivistors ~ it's lOO^^'u solid state! Obsoletes tubn receivers and their warm-up delay, banishes 
ftependence on house current to stay in operation. If current fails or isn't available, the DX-ISO 
rims up to lOfl hours on 8 *'D'^ cells. It will operate from a car's cigarette lighter or any 12 VDC 
jiegHfi\n pronnd mobile or base snnrcc, A 117 VAC power supply is built in, nf couise* The 
l)X-15n is a huskv brute: 14V4 x iVA x OVa" with a massive brushed aluminum extrtided front 
liiincl. sulifl ilinl.il knobs, yrov mi^lal cjibincl, 14 pounds of ([iifilily. 119^^ 

...its the one whh Uk 




1. EXTERNAL 
SPEAKER 



2, STANDARD 
BROADCAST BAND 

3. 1.5M.S MHz 
BAND 



4. 4.5-13 MHz BAND 



5. 13-30 MHz BAND 



6. AUTOMATIC 
NOISE LIMITER 



mna 



SWITCH 



METER 



10. RECEIVE/ 

STANDBY SWITCH 



11. SPEAKER JACK 

12. BANDSPREAD 
CONTROL 

13. BFO PITCH 

14. ON/OFF/ AF GAIN 

15. BAND SELECTOR" 

16. ANTENNA 
TRIMMER 



17. RF GAIN 



18. MAIN TUNING 
CONTROL 



FILL IN AND MAIL ORDER TODAY! 

RADIO r EAST: 730 Commonweal til Ave.. Boston, fVlass. 02215 
* -TIX ' CENTRAL; 2615 West 7tti St.. Fort Wortti, Texas 76107 
SHACK I WEST: 7340 Lampson , Garden Grove, Catif. 9 2641 

Please rush me ttie item IVe checked below. Dept. ZM 

I enclose S ,^ .^^, plus 50(J for postage and hand ting: 



n FREE 1969 Catalog 

n Receiver, 20-150, 
$119.95 



Name (print^) 



a Matching Speaker, 20-1500, $7.95 
n 12 VOC Power Set, 20-1501, $7.95 



Street 



Ci+y 




g 



State 



Easy 



Tuning 




the 



David S. Traer. W4AZK 

625 8th Street, South 
Naples, Florida 33940 



Multi - Element Quad Antenna 



Perhaps the most perplexing and one of 
the most controversial problems facing the 
builder of the multi-element quad is element 
length or tuning. There are many various ar- 
ticles on quads each having an individual for- 
mula for element lengths or method of tuning 
and matching transmission line to driven ele- 
mcnt< Basically, there appears to be two 
methods of approach. Compromise tuning 
for broad banding or '*on the button'' tuning 
for maximum efficiency over a smaller band- 
width. 

Since 1958, when I first erected a four 
element quad, many, many man-hours have 
been spent making measurements with recei- 
vers several miles away, field strength meters, 
vswr meters, impedance bridges, and grid dip 
meters. At that time, there were no fiber- 
glass poles, mounting hardware, or any other 
information available on multi-element quads. 
It became necessary to find a more or less 
foolproof method of tuning and matching 
for maximum energy transfer, with a mini- 
mum of effort and with equipment available 
to the average ham. With these points in 
mind, I set out to find that method. 

Several methods were tried over a period 
of time. In each case, the vswr over the en- 
tire band looked good from the transmitter 
end— with one exception—the driven element 
was always reactive* It should be well known 
that the reactive component of any antenna, 
whether inductive or capacitive, does not 
radiate y in addition, the standing waves along 
the transmission line are not at the same point 
as they would be with a pure resistive load 
mismatched to the transmission line in the 
same degree although reactance is also mea- 
sured in ohms. The proximity to surrounding 
objects does not affect the closed loop of the 
quad as much as it would a yagi type antenna- 
Work may be done on the quad much closer 
to ground level (15-20 feet) if allowance is 
made for a frequency rise of approximately 
25 to 50 kHz at 14 MHz when the antenna is 
put back to forty feet or higher- Therefore^ 



the quad should be tuned to a lower frequen- 
cy to eventually come out at the design fre- 
quency unless all tuning is done at the final 
antenna height. 

One factor that may be difficult for some, 
is that all elements must be made accessible* 
If not accessible from your tower or pole, a 
temporary 2x4 may be set in the ground high 
enough to put the boom of the quad at least 
fifteen feet above ground leveL An allowance 
of 50 kHz should be made at this height- 
Should the diamond configuration be used, 
a slightly higher temporary pole would be 
necessary. From my tests there has been no 
noticeable difference between the diamond or 
the square configuration. Some may argue 
that the two high current points in the diam- 
ond configuration, being farther apart, would 
tend to increase the gain. Theoretically, this 
may be true, but no measurable difference 
has been noted here. 

Let's take an example of a twenty meter 
four element quad in the square configura- 
tion to be tuned to a design frequency of 
14250 kHz. Tuning to be done at a minimum 
height above ground. First, one must buy, 
beg, borrow, or build the following equip- 
ment: grid dip meter, vswr raeter^ antenna 
scope or impedance bridge, and one friend a 
mile or more away. The station receiver, of 
course, is also a must. You may use any of 
the convenient formulas as a beginning be- 
cause in this case we are not interested in the 
length of wire as measured in feet and inches, 
but the results as measured by our equip- 
ment. It is always better to have more wire 
than needed as it is quite easy to cut off any 
excess. Some use number 10, 12 or 14 solid 
copper wire, some aluminum clothes line 
wire, or seven strands of number 20 or 22 
plain old antenna wire; which is available at 
most all wholesale houses. There are now 
many construction articles on multi-element 
quads so we will not delve any further into 
that region- 

String the wire and place all elements on 



32 



73 MAGAZINE 



r 



the boom, shorting all loops so that you have 
completely dosed loops. No transmission 
line is attached as yet. Grid dip the driven 
element to approximately 14200 kHz. You 
need not try to be too accurate at this point. 
Attach your 52 ohm coax to the driven ele- 
ment and to your receiver. Now have your 
friend transmit a weak signal at 14200 kHz. 
Adjust the reflector element for a minimum 
signal from your friend's transmitter. You 
win note a definite null on the S meter of 
your receiver as you tune the reflector. A 
small stub of six to eight inches may be left 
for final adjustments. Cut off all excess wire, 
leaving the stub shorted. An electricians 
^*bug" does a fine job as a shorting *'bai.'' 
Now let's insert a 52 ohm vswr bridge at 
the feed point of the driven element. Turn 
on your exciter at the lowest power possible 
to get a full-scale reading on your vswr meter* 
Adjust the driven element length for mini- 
mum reflected power. This reading will pro- 
bably not go to zero reflected power due to 
the inductive reactance introduced by the 
reflector- Leaving the vswr meter "as is'* at 
its minimum reading, adjust the first director 
(the one nearest the driven element) to fur- 
ther reduce the reflected power reading. This 
may or may not go to 1 : L If not, tune the 
second director in the same manner. The 
second director will have less effect than the 
first director on the reflected power. Proper 
tuning of the two directors with their capa- 
citive reactance affect on the driven element 
will cancel the inductive reactance of the re- 
flector leaving as near as possible a pure re- 
sistive load at the driven element. Remove 
the swr bridge and, using the antenna scope 
or impedance bridge, measure the feed point 
impedance- Should the swr meter have indi- 
cated zero reflected power upon completion 
of the tuning of all elements, the impedance 
measurement should have indicated 52 ohms 
nonreactive on the impedance bridge. In 
other words, the impedance bridge should 
null completely at 52 ohms indicating a non- 
reactive load. In the case of , 1 wave length 
element spacing the impedance should meas- 
ure about 50 ohms or lower With .125 to 
.25 wave length element spacing between 50 
to 75 ohms; -2 up to 3 about 75 to 100 
ohms. Assuming that your impedance meas- 
urement came out around 52 ohms continue 
with the following. If the impedance is either 
higher or lower than 52 ohms, it is necessary 
to now use whatever matching method you 
prefer. Again an example: assume the driven 
element swr would not zero after all adjust- 



ments, and the measured impedance was in 
the neighborhood of 100 ohms. A simple 
quarter wave section of RGllU (75 ohm 
coax) may be attached to the driven element 
and all further adjustments made with the 
swr meter inserted at the junction of the 75 
ohm quarter wave matching section and the 
52 ohm coaxial line to the transmitter. Re- 
peat the previous adjustments, starting with 
the reflector and the help of your friend, ma- 
king only slight adjustments to the reflector 
as needed. AD other adjustments should re^ 
quire only a * 'touch up/' The above proce- 
dure is true regardless of element spacing as 
the phasing of parasitic elements is governed 
by the length of the elements for a given 
spacing. 

Should the impedance be lower than the 
transmission line a Gamma or hairpin (Beta) 
match may easily be used. Refer to such ar- 
ticles or the handbook for adjustments, etc. 
Should the antenna impedance be larger than 
the transmission line use a quarter wave 
matching stub. The quarter wave matching 
section is preferred because of ease of con- 
struction. The Gamma or Beta match may 
also be used with the driven loop closed, but 
more time would be required for proper ad- 
justment. The matching section is simply an 
electrical quarter wave transformer made 
from coax cable of a different characteristic 
impedance following as near as possible the 
result of the formula: The square root 
of the load impedance times the charac- 
teristic impedance of the transmission line, 

Z'p = VZl X Z§ where Zj = characteristic im- 
pedance of the coax for the quarter wave 
transformer, Z^ = antenna or load impedance 
and Zg = source impedance or the character* 
istic impedance of your transmission line. 
Should the load impedance be within a few 
ohms of 50, the transmission line may be 
connected directly to the driven element or 
through a one to one balun. 

While the antenna is still lowered, make a 
bandwidth test with the swr meter at the feed 
point of the driven element or at the trans- 
mission line end of the matching section with 
low power fed to your transmission line from 
your exciter. Make swr measurements every 
50 kHz and plot the curve on graph paper- 
Do not become alarmed if the swr rises very 
sharply at the low end of the 14 MHz band. 
The CW portion may still be used with the 
antenna tuned for the phone portion^ al- 
though the efficiency does diminish. This 
is **on the button" tuning so the reactance 
will be negUgable over the phone portion of 



MAY 1969 



33 



a 



the band. If you use both phone and CW^ it 
might be well to make the design frequency 
near center of the band. Likewise^ the de- 
sign frequency m^y be made in the CW seg- 
ment if you desire- Getting back to the swr 
measurements, you will note that at the an- 
tenna, or the base of the matching section, if 
one is used, the reflected power is ml across 
the greater portion of the design frequency, 

making the true swr unit. Next remove the 
swr meter from the driven element and recon* 

nect the transmission line. There is no need to 
cut the transmission line to any particular 
length— just use random length to suit your 
purpose. Insert the swr meter at the transmit- 
ter end next and again make the full swr met- 
er measurements across the band every 50 
kHz as previously done with the swr meter at 
the antenna. Again, plot the curve on graph 
paper and note the similarity of the curves. 
Due to a multitude of factors, the transmitter 
end of the transmission line swr readings will 
tend to be somewhat lower at the band end 
extremes. 

A dummy load may be substituted for the 
antenna. Heath's '"Cantenna" is a good and 
inexpensive one* The Waters dummy load 
power meter is excellent, but more expensive. 
An rf (thermo-couple) ammeter in the trans- 
mission line at the transmitter is worth its 
weight in gold and much more preferable to 
an in-line swr meter at the same point. Good 
Western Electric and G.E. rf ammeters may 
be purchased on the surplus market for less 
than five dollars. After tuning and loading 
the transmitter to either the dummy load or 
the antenna there will be no change in trans- 
mission line current when switched from one 
to the other and no re tuning of the transmit- 
ter should be necessary. This indicates as 
nearly as possible with available equipment 
whether your antenna is nonreactive or near 
pure resistive* If a Bird Model 43 in-line 

•II a I mark! ^ 

oscillator/monitDr 

• maic«i «ft audibli ton* lo monitor 
tli« fkf of »ny CW trantfnlHef from 
lOMw to I Kw 6^ lOOKc to LOOOHc, 
utmg only an 6" pickup antftnna, 

• can ba itlf-lriggftraij for co4« 
praeifc* op khm t«ttirtg of lolid 
tlnit* <ornpon«nti And circur^. 

• «idt in tunifig yp C^ testing RF 
Oicillalor »rd pow«r errcuits, 
m U tramittor, 2 diodo cifcuil;, 
■pffak«r, ton« ^diuttf AA p*nc«1(, 
l*tt l«4dt, d" ant,, ^ magnetic bai*. 

• cabinet ii 16 gauge black &• clear 
anodif«d aluminurn, 3,4 k 2.3 k 1.2* 
US made €r guaranteeil for I y«ar« 

James Research company ^dep'f; AR-M 
n schermerhorn st^brooklyn ny 11201 



UtD complete, 
ppd usa &can. 
send n check or iri.o, 
floTd by moil only 



wattmeter or equivalent is available, some in- 
teresting overall efficiency measurements may 
be made. Insert the wattmeter at the antenna 
feed point and adjust the transmitter to a 
given plate power input. On all further 
measurements keep the transmitter adjusted 
to the same power input. At frequencies near 
the design frequency the antenna is nonreac- 
tive and there is no reflected power and the 
overall efficiency is indicated. For instance, 

we adjust the transmitter to 500 watts dc in- 
put, the wattmeter indicates no reflected 
power and forward power reads 300 watts 
(with grounded grid amplifiers and 100 watts 
of power output from the exciter, the final 
amplifier should be adjusted to 360 watts 
input as the output from the 100 watts from 
the exciter should appear in the output to the 
transmission line). The overall efficiency 
from plate power input to actual power out- 
put to the antenna would be 60%. This in- 
cludes normal transmission line losses, impe- 
dance transfer from final amplifier, etc. 
This percentage may seem high» but is quite 
attainable with good linear amplifier design 
and proper matching of transmission line to 
a resonant antenna. Now tune the transmit- 
ter to the same power, but to frequencies at 
which the antenna is nonresonant. Note the 
difference in forward power and reflected 
power. Subtract the reflected power from the 
forward power and figure the efficiency 
percentage. Make these same percentage 
measurements every 50 kHz over the band as 
was done with the swr curve- That does it! 
There lies the reason why it is still preferred 
to have an antenna with less frequency excur- 
sion and higher efficiency than one of a com- 
promise nature- 

The preceeding procedures are not inten- 
ded to be the '^ultimate" but will afford the 
"working ham" a less expensive and time-con- 
suming method of getting the most from his 
multi-element quad antenna. Although the 
reference is to a four element quad on a 
thirty foot boom^ the same approach may be 
used with a two or six element quad. The 
forward gain and F/B ration will be as good if 
not better than the average when tuned in 
this method. 

Work has been going on for more than 
three years to broad -band a multi-element 
quad and yet retain a minimum reactive load 
over the entire band. Success seems just ar- 
ound the corner, but the last ten years work- 
ing with the multi-element quad has taken 
its toll. 

W4AZK 



34 



73 MAGAZINE 




The Cla 





i.-^i 



: » ^s^ 



*Pat. No. 3419872 






Jm^TRAf 



///////A/// 



With Patent Approved' Classic Feed System* 

You've been hearing about the Classic Feed System and 
its phenomenal success in three-element configur- 
ations. Now— in response to repeated requests— this 
revolutionary new matching system. Balanced Capacitive 
Matching, has been incorporated into the original six- 
element configuration of DX-proven TA-36 to create the 
new Classic 36. This tri-band beam, rated for maximum 
legal power onIO, 15,and 20 meters, features the Classic 
coax-fed balanced element for more efficient beam per- 
formance, increased bandwidth, and maximum gain. 

As the latest addition to the world-famous Mosley Trap- 
Master line of amateur antennas, the Classic 36 offers: 
frequently'imitatedf never'improved'upon Mosley Trap- 
Master Traps; automatic bandswitching by means of 
exclusively designed, kigh^impe dance parallel resonant 
Trap Circuits; weather' tested Trap'Master construction. 

Satisfied TA-36 owners can convert their beams to the 
Classic 36 with the new TA36/CL36 Conversion Kit. 

The Mosley name is your guarantee: Mosley builds quality 

antennas and stands behind them. Write factory 
direct for complete specifications and performance data, 

including VSWR curves and gain figures. 



Dept, 181 A 



tV 




CJOBO^fffUOA^ m^h& 



i 



4610 N. LINOeERGH BLVD., BRIOGETON MO, 63042 



^^a^m 



The 



Antennascope 
An Effectwe 



W. R. Carmthers, VEZCEA 
256 Alexandra Avenun 
Vtaterloo, Ontario, Canada 



Tool 



There are two types of antennas, com- 
mercial and amateur. A commercial antenna 
is generally designed for one frequency, has 
many acres of ground around it, no obstruc- 
tions and miles of heavy copper cable buried 
underground to provide an "effective" 
ground. These antennas work as de- 
signed - very well* The amateur antenna, on 
the other hand, is just that — an amateur 
design and construction. 

This antenna is subject to all ills, roof 
tops, buildings, trees, TV masts, house elec- 
tric wiring, telephone wires and what not, 
It*s a wonder they work at all! But they can 
be made to work and thousands of amateurs 
make them work. They make them work by 
pruning or lengthening the feeder cable and 
by using an antenna coupler. These are 
always empirical steps, the "let's cut and try 
and see what happens'* method. How much 
better it would be, and a time saver too, if 
we tested our antenna systems electrically 
and knew what was happening and then 
could take intelligent action to put the 
whole antenna system into resonance. 

This fact is well known — an antenna can 
only accept power and radiate properly 
when it is operating at its resonant fre- 
quency. This is no problem for the com- 
mercial people who operate at one fre- 
quency. The amateur, however, wants to 
'*roam the band" and may wish to operate 
over frequencies hundreds of thousands of 
cycles wide, even megacycles wide. How can 
he do this with a fixed antenna system? The 
answer is, he can*t! But he can construct an 
antenna system for a certain frequency and 
take the penalty of reduced radiation when 
he moves far away from it However this 
actually works very well, because each ama- 
teur has his own particular part of a band in 
which he likes to operate — and his friends 
tend to stay there too. On this particular 
spot, the amateur works diligently to ''put 
out a good signals 

The question arises — how can we make 
sure our antenna system is radiating well at 
the particuiaf frequency we wish to use? 
One answer is to use electrical test equip- 



ment to show us what is happening on the 
whole antenna system, which includes the 
antenna and the feed line. 

One of the most useful devices for this 
purpose is the rf bridge, generally called the 
Antennascope* Basic circuitry and values 
were described by WAICCH in the January 
1968 issue of 73 Magazine, page 21 A. It is a 
simple device, inexpensive to construct and 
very effective in results. It is usually 
powered by a grid dip oscillator. Such 
bridges should be used at the junction of the 
feed line and the antenna and will show the 
resonant frequency of the antenna itself and 
the radiation resistance at the feed point. 

Making such measurement up in the air is 
a difficult thing for the average amateur and 
impossible for those whose antennas are 
supported at the ends. If we are w filing, 
however, to accept a small degradation in 
results, we can use the rf bridge at the 
station end if we have a half wave, or 
multiple of a half wave, feed cable. At every 
half wave point on a feeder cable the voltage 
and current vectors are in phase, which 
simply means that the electrical condition 
seen at the end of the cable is repeated every 
half wavelength in the cable. We can use the 
rf bridge then, at the station end of the feed 
line, if we are wilUng to agree that the results 
will not be 100% but reasonably close to it. 
The results will be affected by all the various 
factors that affect amateur antenna reso- 
nance and these effects may give us some 
peculiar results, but they can be overcome 
and the final results may be quite valuable to 
us. 

Let me give you an example to illustrate 
what I'm talking about and to show you 
how effective the use of the rf bridge can 
be: — 

A friend of mine constructed a 40 meter 
inverted V anteima, held at the feed point 
40' up on his beam tower, 66* legs down to 
supports which held the ends about 8* off 
the ground. Feed line was 100' of Twin 
Amphenol cable, velocity factor .68, The 
antenna was difficult to feed, swr was high, 
radiation was poor. He asked me to have a 



r 



36 



73 MAGAZINE 



r 



look (electrical) at it- I took my grid dip 
meter, rf bridge and vtvm. 

The first thing done was to check the 
feed line length. 1/2 wave length at 7,1 MHz 
was 492 X. 68/7,1 or 47.1 feet. Two 1/2 
wave lengths (to get into the station) would 
be 94.2 feet. 

The first conclusion was that the feed line 
was 5.8 feet too long. 

Next Test No, 1 was made u^g the rf 
bridge with results as shown in Fig, 1, the 
results being shown in table form and also 
plotted in graphical form. 



FMC 


ROI 


7.0 


S9 


7 J 


SO 


7,2 


110 


7.3 


119 






"T 
.7 



.a 



—r 
.9 




F MC 



Fig. 1. 100' Feed line Test No- 1. 

It was obvious from this graph that the 
antenna system was resonating outside the 
band as shown by the dotted lines. This test 
was repeated and the results were taken 
down to 6-4 MHz. They showed the system 
to be resonant at 6.6 MHz, 

Test No, 2 was made next using the feed 
line cut to 94.2 feet. Fig, 2 shows the 
results. 



FMC 


R OHMS 


7.0 


4« 


TOS 


di 


7,1 


69 


7.2 


80 


7,S 


IIS 



too 



iA 

S 




Fig. 2. 94.2' FeedlineTest No, 2. 

It was obvious the resonant point of the 
system was rising. 

Test No. 3 was made next^ cutting the 
feed line to 91,2 feet long. Fig. 3 shows the 
results. 



FMC 


HOHMS 




7.0 


43 




7.1 


4e 




7,a 


7e 




7,3 


ai 


1 







100 




Fig. 3. 91.2' Feedlme Test No, 3, 

The resonant point was rising, but not far 
enough yet. 

Test No, 4 was made using the feed line 
cut to 88.2 feet long. Fig. 4 shows the 
results. It was obvious that we were very 



. 



F MC 
7.0 


R OHMS 
4S 


100 












7.05 


47 














7,1 


91 
€0 


75- 












T,Z 






^^ 






7,3 


75 


3 

a 50-^ 

25- 




^^ 


-^ 




1 




, 












7.0 


\ .2 .9 


1 










F MC 






1 



FJg. 4, 88.2' Feedline Test No, 4. 

dose to the resonant frequency of 7.1 MHz 
which my friend wished to use. 

Test No. 5 was with 85.2 feet in the feed 
line. Fig. 5 shows the results. 



r «c 


ROHWS 


TO 


78 


7.1 


61 


7.2 


60 


J.% 


66 




rwc 



Fig. 5, 85.2' Feedflne Test No, 5. 

Test No, 6 was with the transmitter (300 
watts CW) and antenna coupler connected. 
There was no trouble in loading and no 
trouble in balancing the coupler to obtain an 
swr of 1 to 1 ratio. 

The results on the air were interesting^ 



MAY 1969 



37 



a 



■9 



i^^mmm 



5/9+ reports to the Eastern half of the 
U. S. A,, 5/8 reports to Germany etc- Con- 
clusion: The results shown above are not 
precise, nor can they be expected to be 
precise. There are too many unknown fac- 
tors entering the electrical picture, such as 
those which required a shortemng of the 
feed Une, in this example, to somewhat less 
than a half wave length. But the bridge 
showed us the overall picture and suggested 
what was required to be done. The on-t he-air 
results show that it was giving us a good 
picture and a result that was very satis- 
factory for my friend*s needs. 

Why not construct an r/ bridge and check 
you own antenna system? I suggest it will 
pay off and be very informative to you, 
showing you what your antenna system 
looks like electrically and what to do to 
bring your whole system to the resonant 
frequency you wish to obtain. . . . VE3CEA 



Short Cut to Matching 

Tn building an inexpensive, short space, 
two element beam for twenty meters, con- 
siderable difficulty was met in obtaining an 
acceptable match from the feed line (RG-58) 
to the center coil of the driven element (link 
couphng method.. -ref. Radio Amateur Hand- 
book, three element beam for twenty meters). 
The initial set-up is shown in Fig, L 



8G58 FEED 



^ 



DRfVER 
43 TURNS 



UHK COUPLE 



OlfiECTOn 
42 TUANS 



F ig. 1 . Link coupling as in the original set up. 



After initial tweaking, the best VSWR ob- 
tained was a disappointing 3:L Varying fac- 
tors such as changing the number of turns» 
spacing of turns and antenna height resulted 
only in increasing the VSWR, 

Further thought and many aggravating 
trips up and down the ladder resulted in a de- 
cision to use an old approach to the problem 
by going to the ''Gamma Match" method in 
Fig, 2. 

The Gamma match was accomplished by: 

1 . Tying the shield of the RG-58 coax to the 
center turn #21 of the 43 turn center coil of 
the driven element and» 

2. Connecting the coax center conductor to 
the 31st turn on the coil. This gave a starting 
point of 5:1 VSWR. 

With a little hint from the handbook, a 






ADJ, 
t 



IGAMUA ItfATCHI 



Fig* 2. Using the ever popular "Gamma 
Match/' 

140 picofarad capacitor was dug out of the 
"junk box*' and inserted in the coax center 
conductor line,,. going to the tap on the coil 
as in Fig. 3, 



fl6 5S COAX 




43 TURN 
CENTER COIL 

DfilVEN 
EL£MENT 

ADJ. 



DIRECTOR 
fiEF OHly 



140 UUF 



Fig, 3, Adding capacitor for best match. 

The capacitor was set at several different 
positions and minimum of 3:1 was obtained 
at a max capacity setting. This appeared to 
be httle headway for all the trouble, but past 
experience pointed to the possibility that the 
antenna height was a remaining variable not 
yet changed. A little experimentation with 
antenna height (more trips to roof) showed 
best results with it raised just five feet- 

A check of the VSWR bridge showed a 
rewarding 1.5:1 for all our efforts to obtain 
a match. 

Bernard Oliver, K6CZJ 



DX 


QUIZ 


OK, you DXers, 


how are you on pre- 


fixes? Score five points for each correct pre- 


fix. We are in Africa 


this trip. 


Congo 


Republic of 


Republic ,.,„.,. 


Guinea 


Republic of the 


Uganda 


Congo 


Rwanda .,.,.... 


MaK ........ 


Niger ,, 


Central African 


Tanzania 


Republic 


Gabon 


Senegal 


Spanish 


Cabindi 


Guinea 


Fernando 


Mauritania ..„,.,. 


Poo 


Lesotho 


Zanzibar 


Mozambique ,.....,. 


Chad 


Botswana ........ 



You'll find the answers on page 50 No 
fair peeking until you've committed your- 
self to good guesses* 



38 



73 MAGAZINE 



r 



ROHN, as the largest tower man* 
ufaoturer In the United States, 
provides outstanding com* 
mercral quality equfp* 
ment for amateurs. 
We're best known 



tn this field for our 
crank- up, fold -over and 
#25G towers- Like all our 
commercial towers, they' 
dipped galvanized after fabrication 
according to El A specifications. We also 
make commercial hardware and accessor- 
ies amateurs use, too, and it's all designed 
with an understanding of your needs, par- 
ticularly in the area of quality. And don't 
overlook our constant search for new ideas, 
processes and products — Just for you- 
Keep an eye oui for the ROHN name. It's 
well worth your while. 



>: 



ROHN 




Home Office — Factory 

P.O. Box 2000, Pfforia, III, U.S.A. G160I 

Phone 309-637-8416 TWX 309-697-1488 




I 



Systems Office — 

Box 877, Richardson, Texas 75080 

Phone 21 4*AD1-3481 

Western Office 

310 Qumcy Street, Reno, Nevada S95QZ 

Phone 702-322-9300 

Eastern Office 
P.O. Box 2101 
Hanover, Mass. 02339 
Plione 617-826-2511 

Southern Office 

P.O,Box S537, Birmingham, Ala, 35217 

Phone 205-8414789 



fVlAY 1969 



39 



I 




on 




Peter A. Lovelock, W6AJZ 

235 Montana Avenue 

Santa Monica, California 90403 



Those of us restricted to using top-loaded 
verticals on 75-80 meters for fixed station 
operation, are apt to regret the narrow band- 
width inherent in this type of antenna. So it 
was with my Hustler 4-BTV, which performs 
fine over as much as 150 kHz in any selected 
part of the band, but limited my operation 
to either SSB or CW for a given adjustment. 
Since I like to work 80 meter CW DX and 

also ragchew on 75 meter SSB, there just had 
to be a better solution tlian lowering and 
raising the antenna each time I got a yen for 
the alternate mode of operation. 

There was, and it was as simple as instal- 
ling two top-loading coils -in my case the 
Hustler type RM-75< 

This was accomplished by fabricating a 
suitable mounting bracket out of VxYa^ 
aluminum stock, as shown in the figure. The 
two *'ears," 45 degrees to the center mount- 
ing surface, permit the two coils to be moun- 
ted physically 90 degrees to each other, min- 
imizing intercoupling. The bracket is moun- 
ted by the center hole to the 3/8"-24 stud 
atop the 4-BTV, on which a single RM-75 
loading coil is normally attached. The stud 




(%] 



HCiLES 



o 


o' 1: cr 

1 1 



TOP ViEW 







1 


1 


■' 


1 








1 


i 






V 


lew o 


ft 


he ant< 


snna ir 


1 use. 







Fi0. 1. The mounting bracket for two RM-75 
foading coils. 



being only about Vi'* long required filing 
down the bracket thickness to 1/8" at the 
mounting point, in order to secure the brack- 
et with a 3/8«24 nut. r'xl/8'* stock is also 
available, but it was felt this would be a bit 
flimsy, causing the "ears'' to flap in a stiff 
breeze, with detrimental affects on resonance 
and loading- Anyway, both kinds of stock 
are to be found in the *'Do It Yourself al- 
uminum rack in weU equipped hardware 
stores* The coils are attached with 3/8-24x'/2" 
bolts using washers, plus a split lock-washer 
to take up the extra bolt length and ensure 
that the coils won't come loose* 

Tlie pictures show the finished product - 
One coil is resonated by it's whiplet to 3900 
kHz and the other to 3550 kHz, The anten- 
na resonates and loads with low SWR at both 
frequencies with no interaction between the 
coils, and I can now enjoy operation on my 



40 



73 MAGAZINE 



PRESENTING THE ALL NEW 



*0^i*i ' 



r4i/kt*J^<L**ii* 



i *r* 



ir* 



%* 



iiUi 



-UN 



ALL BAND TRANSCEIVER 
PREAMPLIFIER 



il 



&j* 



PW*** 



- 6 THRU 160 METERS - FEEDS 2nd RECEIVER 

Model PT, with built-in power supply, transfer relay, connecting 
cables, wired and tested. Amateur Net ...$59,95 

■ A frame grid pentode provides low noise figure with ability to handle strong signals, 
greatly improving the sensitivity of the receiver section of a transceiver. 

■ A unique built-in transfer circuit enables the PTto by-pass itself while the transceiver 
is transmitting. The PT also feeds the antenna input of a 2nd receiver as well as 
muting it. AMECO 

DIVISION OF AEROTRON, INC. ■ P. 0. BOX 6527 • RALEIGH, N. C. 27608 







Mounting details showing the two ''ears/' 

two favorite sections of the band without 
roof -climbing. The assembly easily withstood 
recent 55 mph wind gusts. 

Of course, this principle can be applied to 
any sim0arly top loaded vertical, with a suit- 
ably made bracket* Hmmm! If I made a 
bracket with ears parallel to the mast, I could 
mount more than two coils, horizontally, 
and 90 degrees to each other , giving me addi- 
tional band coverage. Who is going to be first 
on thek block to have "four on top?" or 
even five? ,,.W6AJZ 




"BJtmeyl No wonder I'm not copyjn'! 



t %tt 



MAY 1969 



41 



J 




Measuring Antenna Gain 



John J. Schuhz, Vf2EEY/l 

40 Rossie Street 
Mystic f Conn. 06355 



H 



Some basic methods are described for 
measuring antenna gain using a reference gain 
antenna as well as methods that can be used 
when a reference antenna is not available. 
Even for those who do not plan to use the 
methods described, reading and understand- 
ing them will provide a better insight into the 
meaning of an antenna gain figure. If one 
likes to experiment with antennas, either 
building arrays or experimenting with new 
forms, a continuing problem is how to mea- 
sure the gain of an antenna. Of course, the 
proof of any antenna will always remain in 
how it performs in actual operation. Also, 
gain is just a number and by itself doesn't 
convey any information about the overall ra- 
diation pattern(except to say that it is formed 
in some directive manner). Nonetheless, it is 
often handy to be able to talk about some 
gain figure for an antenna. 

One can estimate gain by using a new an- 
tenna in the same mounting position as an an- 
tenna of known gain and comparing many 
signal reports 5 switching back and forth be- 
tween the two antennas, to obtain some 
reasonably meaningful gain figure for the new 
antenna. The procedure can be rather tedi- 
ous, however. This article describes various 
ways by which the gain of an antenna can 
be more accurately measured, whether one 
has an antenna of known gain available or 
not* Because of physical restraints and the 
interference produced by atmospheric noise, 
the described methods work best with VHF 
antennas. However, with care^ the methods 
can be used with well elevated high-frequency 
antennas. Another way to check the gain 
capabilities of a proposed high-frequency an- 
tenna design would be to first construct a 
scaled VHF model of the antenna. Such a 
model is also very useful to study the impe- 
dance and matching conditions necessary for 
best antenna performance. 
Basic Method 

Fig* 1 illustrates the basic equipment setup 
which is necessary to measure antenna gain. 



POWER 
TRANSMITTED 



PQWEn 
RECEIVED^ 
POWER 
TRANSHITTED X 



\ 




TX 




Fig. 1* Baste free-space transmission form- 
ula between antennas. Antennas are in the 
same plane and the transmrssion Hne between 
the equipments and antennas have negligibte 
loss. Loss, if present, can be included as a 
seating factor (i.e. a total line loss of 2.5 db 
wilf reduce the power received by a factor of 
.55). 

The gain of the antennas and the power 
transmitted and received are related by the 
standard transmission equation; 

"transmit ted/"received=G^Gj (X/47r D)^ 

G^ and G^ are the numerical values of the 
gain of the transmitting and receiving anten- 
na, respectively. The term in parenthesis is 
simply a constant. X is the operating frequen- 
cy expressed in meters and D is the distance 
between the antennas also expressed in met- 
ers. 

The above equation is true so long as the 
antennas operate with essentially plane wave- 
fronts- That is, if the antennas are too close 
there will be an appreciable phase difference 
between the signal which one antenna receives 
from the center and the edges of the other 
antenna. So, for good measurements, D ijii 
the above equation should at least be equal 
to about 2L^/X. L is the longest lineal length 
of the antennas being used and X is the oper- 
ating frequency. For instance, if an antenna 
were to be tested on 2 meters which had a 
maximum length of 3 meters, or about 10 
feet, the test antennas would have to be sep- 
arated by at least 9 meters, or about 30 feet. 
Generally, there is no difficulty in meeting 
the separation requirements unless one is 
dealing with very large antennas at very low 
frequencies. 

The necessary power measurements can be 
accomplished in several ways, A wattmeter 
can be used in the transmitting antenna's 



42 



73 MAGAZINE 



transmission line or the r/ voltage across the 
line measured and the power calculated- The 
line itself should be operating as close to a 
1:1 swr ratio as possible. The receiving an* 
tenna power can be measured in essentially 
the same manner or if the gain of the receiver 
is accurately known, it can act as a power in- 
dicating device. Again, the impedances be- 
tween the antenna, transmission line and re- 
ceiver input must be correctly matched. Still 
another method is possible if only the power 
output of the transmitter can be measured. 
The transmitting power is adjusted for some 
convenient reference level on the receiver 
(receiver avc is off). The receiver "S" meter, 
if it is the type that functions with the avc 
disabled, or an audio output meter, if the 
transmitter is tone modulated, can be used. 
The transmitter is then connected to the re- 
ceiver and its output level slowly increased 
(usmg an attenuator network or by varying 
an operating voltage which controls the out- 
put power) until the same reference level is 
obtained. The power level required will be 
the same as the received power. 

If one operates only on a specific VHF 
band and wishes to construct a sort of "in- 
stant reading" gain meter, this can be done by 
using a dipole as the receiving antenna and 
placing an rf rectifier circuit and meter dir- 
ectly at its terminals. As long as the distance 
between the transmitting antenna and the re- 
ceiving reference antenna is kept constant and 
as long as the input power to the transmitting 
antenna (of unknown gain) is always the 
same, the meter can be calibrated directly in 
terms of antenna gain. It is only necessary to 
use several antennas at the transmitting end 
of known gain first in order to establish the 
caUbration of the receiving antenna ''gain'' 
meter. Such a device can be a great deal of 
fun and use during competitions at field days, 
etc. for the best antenna designs. Aside from 
the distance and power considerations men- 
Lionedj however, tlie only requirement for 
the FD ''wonder*' antennas tested is that they 
be capable of producing near unity swr in the 
transmission line to the transmitter. Unless 
this condition is met, the "gain'' meter read- 
ings will not be valid in either an absolute or 
comparative sense. The basis for the calibra- 
tion of such a meter should become clearer 
from the following test situations. 
Gain Using a Standard Reference Antenna 

If one has constructed an antenna of 
known directivity gain and wishes to deter- 
mine the gain of an untried antenna design, 
the setup of Fig. 1 can be used. The trans- 



mitter output power and received power are 
measured and the gain is calculated from the 
formula previously given, knowing the anten- 
na separation and the operating frequency 
(using the untried antenna as either the trans- 
mitting or receiving antenna). For instance^ 
if the reference antenna used is considered 
to have a gain of 1(0 db), the original form- 
ula can simply be restated as: 

G=(47r D/X)^ "received/*^transmitted 
Thus, if an antenna were tried on 2 meters 
at a distance of 10 meters and the power 
received were l/IO of a watt for a 10 watt 
transmitter output, the gain would be: 

G = (47r 10/2)2 l/io = 36 = 15.5 db 

1/10 
This gain is in reference to the gain of the re- 
ference antenna (a ^/ik dipole, for instance). 

In practice, however when one can move 
the antennas under test about easily, a much 
more simplified procedure is possible. The 
transmitter is connected to some ava Cable 
antenna. At a reasonable distance away, the 
standard or reference antenna is connected to 
a receiver- The transmitter power output and 
receiver gain are adjusted to produce some 
convenient reference level- The transmitter 
power output is noted. Then, the antenna 
under test is substituted for the reference an- 
tenna- The transmitter power output is re- 
adjusted to produce the same reference read- 
ing on the receiver. If the test antenna re- 
quired only 1 w^att of transmitter power to 
produce the same receiver reference level as 
when 10 watts were used with the reference 
antenna, the gain of the test antenna is simp- 
ly 10 4 1 or 10, which also happens to be 10 
db. Remember that the numerical power 
ratio must be converted using a db power 
curve for db gain expression. Again, the an- 
tenna gains obtained by this method will all 
be referenced to the assumed unity gain 
(0 db) of the reference antenna- 
Gain of Two Identical Test Antennas 

Suppose that one had two identical anten- 
nas and did not know the gain of either nor 
had any reference antenna of known gain 
available- Surprisingly enough, the gain of 
the test antenna design can still be easily 
found. If the gain of both antennas in the 
test setup shown in Fig, I is the same, the 
original gain formula is re-arranged in the 
form: 

G=47r D/X "received/Mransmitted 

The received power and transmitted power 
can be measured with some specific antenna 
separation and the formula will yield the gain 



! 



MAY 1969 



■ 



43 



J 




of either antenna (as a numerical value, not 
indb). If the received power cannot be meas- 
ured directly, the receiver can be used just to 
establish a reference level and the transmitter 
connected alternatively to one of the test 
antennas and then directly to the receiver to 
establish a power ratio that can be used in 
the formula. 

The gain figure obtained from this proce- 
dure is mathematically related to a so-called 
isotropic antenna which radiates equally in 
all directions. A ^zk dipole antenna when 
used with this procedure should show a gain 
of slightly over 2 db— since it does concentrate 
its radiation broadside to the line of the an- 
tenna. Thus, if more comphcated antennas 
are checked by this method the gain figure 
obtained must be reduced by 2 db if a com- 
parison is desired with other antenna gain 
figures which use a VzK dipole as a reference. 

This procedure is frequently used to estab- 
lish the gain of reference or standard antennas 
against which test antennas can be compared. 
Gain of Three Different Test Antennas 

Suppose that one had a group of three 
antennas none of which appear to have the 
same gain and no reference gain antenna is 
available to compare them against. By a vari- 
ation of the previous procedure, the gain of 
all three antennas can still be established. 

The antennas are arranged as shown in 
fig, 2. The distances between them need not 
be equal but is assumed so to simplify ttiis 
description. Using the basic transmission 
formula and when station 1 transmitts, the 
following formulas are obtained, each of 
which produces a simple number when the 
measured values are inserted. 

Gj G2 = (47r D/X)2 ^rec. 2/Ptrans- 1 = A 

Gj G3 = (47r D/X)2 Prec, 3/Ptrans. 1 = B 

Next station 2 transmits and the following re- 
lationship is determined: 

G2 G3 =(4tt D/X)2 Prec. S/^trans, 2 = C 

Since three constants and three interrela- 
ted gains are concerned, the gain of each an- 
tenna can be found: 
G|= AB/C G2= AC/B 63= BC/A 

Again, the gains will be in numerical form 
and must be converted to db values, AlsOj 
the gains will be referenced to a theoretical 
isotropic antenna and must be reduced by 2 
db for comparison to gains related to a Vzk 
dipole. 
Precautions 

The basic transmission formula used actu- 
aUy derives from optic equations, although it 
is the standard radio transmission formula. It 





I 

I 

1 




'O 



\ 



\ 



X 



\ 




Fig, 2, As described in the text, the gain of 
three dissimilar antennas may each be found 
afthough the gain of none of the antennas is 
known. D, distance between antennas, need 
not be equaL The only requirement is that 
all the antennas have the same polarization, 

does not take into account any other signals 
being present except the transmitted one in 
space. At high enough frequencies, this con- 
dition is reached with radio transmissions but 
at lower frequencies an antenna will receive 
noise signals as well as the desired signal - 
Therefore, allowance must be made, if possi- 
ble, for the error caused by noise reception. 
If the received power levels are high compared 
to the received noise level , the noise effect 
may not be significant. At great distances 
and with low power levels meaningful results 
cannot be obtained, 

Some other general precautions are: 
L Both antennas must be oriented for maxi- 
mum signal before measurements are made. 
It can happen that maximum radiation does 
not coincide with the geometric center of an 
antenna, 

2- The formula is based on linen^f-sight 
transmission. Reflections, including those 
from inadequate antenna height, should be 
avoided. 

3. The antennas must be separated sufficient- 
ly to produce a plane wave. 

4, Correct impedance matches must exist 
throughout the transmitting and receiving 
terminals. 

5* If the receiver is used as a power level in- 
dicating device, its gain must be reasonably 
stable or should be frequently checked. It 
must be operated in its linear range without 
overloading and with its avc off. 

The use of a low power transmitter whose 
power output can be readily varied was as- 



44 



73 MAGAZINE 



sumed, A signal generator of sufficient out- 
put power can also be used. If one uses a 
method such that connection of the trans- 
mitter to the receiver for reference level set- 
ting is not necessary, a transmitter of fixed 
power output of any level can be used. 
Summary 

When commercial laboratories make gain 
measurements using some of the methods des- 
cribed they take elaborate precautions to av- 
oid effects that will alter true gain reading^. 
However^ even with simple equipment— even 
the regular station transmitter and receiver in 
many cases -meaningful results can be ob- 
tained. 

Even if one does not measure the gain of 
any antennas, the material in this article 
should give a better insight to many ama- 
teurs as to how the gain figure for an antenna 
is determined. Particularly, it should clarify 
how antenna gain is always related to some 
reference. Thus, unless one knows the ref- 
erence, one can easily read good-sounding 
but not really useful gain figures for some an- 
tennas. 

Finally, it should be appreciated that gain 
is only a numeric and not the only meaning- 
ful characteristic of an antenna, although too 
to gain figures- Other factors such as the 
vertical and horizontal radiation pattern 
forms, front-to-back ratio, impedance, band- 
width, etc* are just as important andj indeed, 
in some applications more significant for best 
communication than gain. ..-W2EEY/1 



LEARN R/IPfO 




Afbuifl fftnttrnt threi W* 
LP's 214 hf. mstruetiQEi 



THE EASVWAYl 

« No &Qoki To Read 

• Ho VUuot GImmUks 

To Distract You 
« Just Listen And learii 

ieated on modem ptychologlcot 
techniquti— This courie will toko 
you b«yond 13 w,p»m. In 
LESS THAN HALF THE TIMEI 

Also dvoiloblo on moffnotlc topo. 
Seo your deafer nowl 



EPSILON P^ REeOR0$ 



206 Eoft Ffofit StrMil« Flmnco^ Colorado 



€8K7B 



3-I2AX7 
IN PARALLEL 




CONNECTED 
TO I2AX7 
TERMLNAtS 



®TORCVR 



ANT ,01 

r®-IHj 1 

®ANt 



100 



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400RV ,^( 





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50Mt 
250 V 



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Fig, 1. A different TR Switch, 



A Different TR Switch 

The TR Switch described in May 1963 73 
Magazine on pages 12 and 14 has undergone 
a metamorphosis or change for the better. 
While in some areas of the country the 
grounded grid configuration will function 
well, it behooves the amateur in a metropol- 
itan area, especially where there are several 
marine, coastal, point to point commercial 
stations operating, to use a different circuit. 
The rf chokes^ especially the one in the cath- 
ode of the grounded grid tubes, have a self 
resommt frequency and lo and behold, com- 
mercial stations can be heard in the back- 
ground. Weakly, but still there. No amount 
of decoupling will eliminate them. Different 
values of chokes can be used^ but then a sac- 
rifice in gain on the amateur frequencies re- 
sults. 

The most satisfactory circuitry tried to 
date uses a cascode rf stage lightly coupled 



to the transmission line, and a cathode follow- 
er output to match the receiver input imped- 
ance. A tube rectifier is used as an rf rectifier 
to provide dc voltage bias on transmit times. 
There is no time constant— it is instantaneous, 
for CW, in order for fast break-in. When using 
SSB, the bias holds long enough between syl- 
lables so that the receiver stays blocked as 
long as you keep talking. When receiving, 
the rectifier has no effect, unless a kw station 
next door fires up. In that case, he will create 
enough bias in the TR switch to prevent over- 
load of the set. It will lower the gain of your 
receiver, but without this effect, you would 
have another kind of trouble. You would 
probably go to the other end of the band or 
change bands. It will be apparent to the ex- 
perienced constructor that this unit can be 
used as a tuneable preselector merely by sub- 
stituting the 1 mh Lj r/ choke with suitable 
tuned circuitry. M. C. Smith, W6GMC 



MAY 1969 



45 



^ 



n 



QRP - A New World to Conquer 



Amateur radio has been getting more ex- 
pensive and more complicated for those in- 
terested in building their own gear. It may 
come as a surprise to discover there are some 
hams who are finding ham radio simpler and 
more challenging. These unusual hams are the 
QRP operators, trying to use lower and lower 
powers to cover greater and greater ranges. 
For the QRP'ers a single transistor rates as a 
powerful transmitter, and communications 
may be maintained at power input levels so 
low they are hard to measure. Could you use 
your signal generator for a transmitter? If it 
is stable enough, yesi But it would be too 
complicated for a really convenient QRP rig- 
QRP achievements are a real eye-opener* 
See Fig. 1, Powers much less than typical 
flashlight levels can achieve communication 
over hundreds or thousands of miles. Trans- 
mitter cost is smaU; there are no high voltages, 
and antenna systems typically range from 
Joysticks to carefully installed dipoles. The 
emphasis is on operating skill and on pa- 
tience which gets you on the right frequency 
at the right time. At QRP levels you do not 
blast the opposition, you wait until he fades 
or quits. Or you learn to hear through hira, 
and somewhere in there you become a real 
radio operator. In the QRP world the quality 
of the man is more important than the qual- 
ity of the rig. The emphasis is on operating 
skill and patience. That is a refreshing change 
and this new perspective has proven reliably 
popular. 

Freq, Mw Range Mi J 
QSO Time MHz Input Mites W* eq. 



AtlhuT Child. W6TyP 
1485 Pine Street #407 
San Francisco. Cai, 94109 



W8UUJ/6, CaL 
WB2GFQ, NJ. 
W70E, Wash, 
WA9DEU, Hi. 



4 pm 7.015 33 

12 pm 7.142 50 

9 am 7.015 100 

7 pm 7-015 500 



WA8JXQ, Ohio 8 pm 7.142 500 



273 8,200 
2565 51,300 

680 6,800 
1840 3,680 
2110 4,220 



AH QSO's by calling CQ. None were arranged. 

Fig, 1* Log excerpts. Every one of these 
contacts is above the basic 1,000 mtles per 
watt achievement that gets you going in 
QRP. 

A world-wide organization of QRP'ers has 
developed. Membership is about 3,000 radio 
amateurs, living in 50 countries. It may be 
these people are the very best radio opera- 



tors in the world, since they routinely try to 
achieve effective communication at power 
levels comparable to the unwanted emissions 
from much amateur gear and far below thni 
from some commercial broadcast transmaieis- 
And, they succeed, setting records of thou- 
sands of miles on milliwatts of power. T 
instance, you can talk from San Frantustu, 
California to South River, New Jersey, on SO 
milliwatts input. It's an established r 1 
Art Child, W6TYP, writes he has been try- 
ing to make contact with QRP'ers in Japan 
and ZL land. Some entries from his log 
pear in Fig- L Previous results indicate he'll 
succeed since he is using his big rig for this 
project. It runs 500 milliwatts. Some other 
of Art's achievements are a IVi mile QSO on 
12 microwatts for 200,000 miles per watt and 
a 354 mile QSO on 354 microwatts for one 
million miles per watt, 
QRP Recipe 

Interested? Find a good receiver, or make 
up something from scratch- A good possibi- 
lity appears in the 3-tube superhet described 
in the October 1968 issue of 73 Magazine. 
Perhaps you could do something with the 
regenerative detector circuit appearing in the 
same issue. And wliile you're working r : 
the receiver problem (which will probably 
cost more than anything else) get a letter off 
to the QRP Club's corresponding secreufy 
for additional information on activities and 
memberships. That goes to F. Behrn;:'n, 
K7LNS, 3425 S.E. King Road, Milwaukee, 
Oregon, 

Next step is a good antenna. There is plen- 
ty of information around about antenna dcs- 
ign and construction, and QRP work simply 
makes quality more emphatically necessary. 
The difference from a normal antenna will ap- 
pear in quality, rather than expense, and this 
is largely a matter of care and workmanship. 
Installing and tuning a really effective anten- 
na will require some test gear, and recent 
issues of 73 Magazine can offer material to 
help you out. A simple antenna bridge may 
do more for you than an swr meter, since you 



46 



73 MAGAZINE 



may not have enoughs/ available to energize 
the meter. For many ideas see 73's special 
Antenna issue. May 1968. 

As you get this set up you can think about 
your transmitter. Crystal control is preferred, 
so that once other QRP'ers know where your 
signal typically appears on their receiver dials, 
there will not be tuning questions with very 
weak signals. And you will appreciate the 
same reliability in their signals. On 40 met- 
ers the best frequencies are 7,015 or 7.142 
MHz. 

A typical circuit appears in Fig. 2. Few 
components could be pared out of this one. 
You will want to do some experimenting with 
this circuit, so start with a good high-frequen- 
cy silicon or germanium transistor, use IK 
ohms in the emitter circuit, and try 82K ohms 
in the base circuit. Place an mF as emitter 

by-pass, and a few picofarads in the base cir- 
cuit to control feedback. C3 and LI are tuned 
to the operating frequency and if LI is a 
piece of Airdux, the antenna tap is easily 
moved up or down. Start with the tap close 
to ground, since antenna loading reduces rf 
available for feedback and at some point will 
cause poor keying. Listen to the signal on 
your receiver. 




^JOYSTICK' 



1/4 TO SV 

Fig, 2- This could be the simplest transmft* 
ter circuit ever publfshed in 73 Magazine. 
Inexpensive, too. The "Joystick" antenna 
is in the same room, eliminating coupler, 
transmission fine, etc^. and tapping up the 
coil increases loading. When you can get 
out with this, you are learning to be a really 
good operator. 

International's printed-circuit crystal os- 
cillator can also do a nice job as a transmitter. 
The print ed-circuit construction is very neat, 
and the kit sets you back S235 postpaid- 
See October issue of 73 again, page 5. The 
crystal runs another S3. 75, specify the fre- 
quency. And another dollar should get the 
r/we!I started toward the antenna* 

Finishing up the rig, you put a TR switch 
in the antenna system somewhere and you 
are in business. The transmitter frequency is 
located during tests by tuning the receiver to 
pick up the transmitter—you don't do this 



with a kilowatt! with key down. The receiver 
would probably not be harmed if you fed the 
transmitter's entire output into its front 
end and in some station setups you might 
have a little difficulty finding the transmitter 
signal, but a clip lead will help you out. Bet- 
ter be careful on principle, though, if your 
receiver has a solid-state front end. 

Finally, start calling. It will take patience. 
After all, the air is full of high-power opera- 
tors, some of whom tend to ignore signals 
under S9 or so. Yours will be one of these. 

Soon you will learn to operate odd hours. 
Perhaps the honorable art of rage hewing will 
appeal to you, again. And you will wake up 
sometimes in the middle of the night think- 
ing about a QSO, and why not? You are 
likely to become an early bird, early to bed 
and early to rise. This is said to offer valuable 
benefits unrelated to ham radio, and it also 
gives you a fantastically quiet band to operate 
in. The signals seem to sound different at 
this time of day Just before the sun is coming 
up. It is an experience you shouldn't miss. 
QRP Performance and Records 

Communications at QRP show a very 
strong dependence upon propagation condi- 
tions. On 40 meters, for instance, the best 
results are achieved late at night, as you might 
expect* But at QRP you cannot ignore the 
facts and vagaries of propagation conditions. 
They just jump right out at you, and you 
will soon become interested in the fluctuat- 
ing conditions of the ham bands. 

Once contact Is made at, say, high power 
of 500 milliwatts then you can start rag- 
chewing, QRP contacts, unlike DX contacts, 
may go on for extended periods as you and 
your contact crank down the power again and 
again, trying to achieve effective communica- 
tion with the smallest transmitter power in- 
put. 

When your log shows you can get a 1,000 
miles per watt certificate from the QRP Club 
you are starting to achieve results. But the 
records are very much better than that^ and 
recent work includes contacts on 40 meters 
ranging from 325 miles at noon to 2565 miles 
at 11:00 p.m,, local time. On 50 milliwatts. 
That's better than 50,000 miles per watt. One 
million miles per watt is possible and has been 
achieved. Such records are unusual and defin* 
itely worth working for. Aside from the fact 
they offer an interesting challenge of the very 
best kind, you are sure to meet unusual and 
interesting people along the way. Don't miss 
the opportunity to enjoy QRP operation. 

„.W6TYP 



MAY 1969 



47 



The Galaxy 

GT - 550 Transceive r 



Petei A. Lovelock, W6AJZ 

235 Montana Avenue 

Santa Monica, California 90403 




A decade or so ago transceivers came into 
being primarily for mobile applicalion. Al- 
most as an afterthought manufacturers tnade 

available AC' power supplies for alternate fix- 
ed station use. Subsequent trends have caus- 
ed transceivers to evolve in cumpiexlty (and 
size) to become complete, single package sta- 
tions; some with an array of controls calcul- 
ated to send a computer programmer into 
frenzied rapture, Bui have you ever tried to 
fit one of these integrated jobs under the dash 
of a Mustang? Or juggle a bank of knobs nev- 
er designed for compatible freeway opera- 
tion? 

When Galaxy Electronics introduced their 
model in and V transceivers, it was obvious 
they had the mobile ham in mind as evidenced 
by functionally located controls, a tuning dial 
on the left side for optimum driver manipu- 
lation, and dimensions ideally suited to under- 
dash installation- And a lot of fellows dis- 
covered that, with an outstanding receiver 
circuit and 300 watts PHP input, the Galaxys 
did an excellent job in the shack. Their fea- 
ther weight and easy mobile mount made dual 
usage a snap* 

The model V Mk 2, besides increasing in- 
put to 400 watts PEP, also added features 
for the CW operator such as sidetone, and 
plug-in options for semi-break in and a 300 
Hz receiver filter. The V Mk 3 incorporated 
final tubes capable of 500 watts PEP, 

Galaxy also developed a line of accessor- 
ies for full fixed station flexibility with their 



transceivers, while retaining the inherent si in- 
plicity, desirable for mobiling, in the basic 
transceiver. This also permitted the buyer the 
choice of paying only for those feaiurcs re- 
quired for his particular motie of operation. 

Maving used a Galaxy V Mk 2. shared mo- 
bile and fixed- for a couple of years. 1 could 
testify to its performance, stability and rug- 
ged construction on the liighway, while 108 
countries and a lot of good CW work with an 
apartment trap vertical left little to be desired 
at home. With this experience, it was diffi- 
cult to conceive that much room was left for 
improvenienl.,"that was. until at the recent 
SAROC convention, 1 witnessed the unveiling 
of the Galaxy GT-5 50. 

Gone was the turmer. somewhat austere, 
front panel to be replaced with contempor- 
ary styling guaranteed to gain living-room ac- 
captancc from the most discriminating XYL 
(mine). While keeping the same weil-arranged 
controls, now with skirted knobs, a new sin- 
gle-scale. 500 kHz dial climmates the second 
scale that formerly reversed frequency direc- 
tion for tuning 20 meters. Now CW and 
phone segments have the same dial relation- 
ship on all bands-a pleasure for CW DX band- 
hoppers like me. The familiar two-speed 
tuning knob is supplanted by a massive, 2Vr 
diameter, single speed knob with plastic in- 
sert finger spinner. The spinner permits 
traversing the entire 500 kHz range quicker, 
and more easily than the wrist switching ac- 
tion required with the old two speed control. 
The 72:1 ratio tuning is velvet smooth and the 
kingsize knob gives finger-tip precision with 
no discernable backlash, even v^'hen using my 
narrow bandwidth CW filter. 

Black on white tuning and S-meter dials, 
indirectly lighted behind rectangular wind- 
ows, make for easy reading and enhance ihe 
new styling. 

A study of the schematic proved that the 
GT-550 is based upon the tried :ind true cir- 



p 



48 



73 MAGAZINE 



F 



cuitry developed through the earher Galaxy 
series, with numerous significant improve- 
ments. The new parallel 6LB6 finals, together 
with a redesigned driver stage, provide im- 
proved linearity and ALC action for 550 watts 
PEP input. On CW the final operates at 360 
watts input with reduced screen voltage for 
maximum tube life. As in previous Galaxys, 

the TUNE mode may also be used for CW op- 
eration, with input power continuously var- 
iable by the MIC/DRIVE control, from a frac- 
tion of 1 watt up to 250 watts. 

Many circuit changes noted indicate con- 
tinuing effort for peak performance in both 
receive and transmit modes. The ahready 
sensitive receiver circuit has been made even 
more so on the GT-550, as is particularly ap- 
parent on the ten meter band. This is where 
so many receivers show a drop-off in perform- 
ancCj but the GT-550 S+N/N ratio is extreme- 
ly good. An added crystal for vfo hetrodyning 
has eliminated the need for tliat separate 
scale on 20 meters. Improved high and low 
voltage regulation includes provision for ac- 
curately adjusting the regulated 12 vdc used 
for the vfo, and also brought out to a rear 
panel jack for accessory operation. ALC 
control voltage is also brought to a rear jack 
for use with a linear amplifier, and is handy 
for plugging in a vtvm to observe where ale 
action begins relative to plate current peaks 
when setting the MIC gain control. Another 
added jack for the external vfo accessory, 
obviates mnning coax through a rear panel 
hole to a chassis jack, as in earUer Galaxy 
models. 

Those operators who periodically check 
alignment to maintain top performance, wiU 
be glad to know that mechanical design of the 
GT-550 has made all alignment procedures 
possible from the chassis topside* No need to 
remove the bottom plate and balance the 
unit precariously on one side. In fact, the 
GT'550 can be completely aligned in its nor- 
mal operating position by merely removing 
the top cover. Even RC 'swamp' circuits 
required for accurate adjustment of double 
tuned transformers, are built in- Just short- 
ing a chassis test point to ground with a screw- 
driver swamps one winding while the other 
is being peaked. A vtvm chassis mounted 
test jack aids in alignment. 

The bank of five band-he trodyning crystals 
are mounted atop the chassis for accessi- 
bility-a convenience for operators wanting to 
substitute crystals for extended 1 meter or 
MARS frequencies- 

The single piece top cover can be lifted 




Interior view of the GT-SBO Transceiver, 

off, or slid back on the unit, for easy access 
by removing four screws. New design permits 
removing the final compartment shield with- 
out having to take off the bottom plate. The 
same basic dimensional configuration main- 
tains the GT-550's adaptability to mobile or 
fixed installations, and the appearance is 
equally pleasing in both. 

Like its predecessors, the GT-550 comes 
with an individual frequency drift calibra- 
tion chart, as measured at the factory prior 
to sMpment- Mine indicated a maximum 
warm-up drift of 140 Hz in the first 20 min- 
utes, after which stability remained within 
a range of 1 Hz for the 40 minute balance 
of the test period. This degree of stability 
has been borne out in actual operation. 

Checking the actual power output with a 
Waters Dummy Load Wattmeter Model 334, 
the following maximum readings were ob- 
tained when loaded according to instructions: 

TUNE mode: 160 watts, CW mode: 280 

watts, 

SSB mode (1 kHz sine wave to MIC input): 

400 watts. 

The GT-550 can be powered either by the 
AC-400j a new heavy duty supply with switch 
selection for 115-230 vac, 50-60 Hz input, 
and solid state rectification; or the GIOOODC 
supply for 1 2 vdc mobile installations. 

All in all, the GT-550 offers a lot of 
transceiver at moderate price. Add plug-in 
options for the CW man, and a line of acces- 
sories including plug-in transistorized 25 kHz 
calibrator (for those new band limits); com- 
plimentary styled external VFO, 2 kw PEP 
Linear Amp., Hybrid Phone Patch with tape 
recorder facilities, speaker console that ac- 
commodates the AC^OO supply, and an RF 
Console that switch selects up to five antennas 
plus dummy load— with buUt-in forward/re- 



1 



MAY 1969 



49 



p 



fleeted wattmeter. •and you have building 
blocks for a home station tailored to your 
needs, around a state-of-the-art transceiver 
ideally suited for mobihng- 
Technical Specifications 

Frequencv Coverage-3.5^.0; 7.0-7.5; 14,0 
14.5; 2Lb-2L5; 28.0-28.5; and 28.5-29.0 
MHe with crystals supplied. Additional ten 
meter and MARS frequencies with accessory 
crystals. 

Dial Calibration-5 kHz increments, 500 kHz 
range, with single linear scale-over 12 inches 
of bandspread. 72:1 ratio vernier tuning- 
Operation Modes-Selectable USB-LSB, sup- 
pressed carrier, PTT or VOX (with optional 
accessory). Shifted carrier CW, manual or 
semi-break in (with vox accessory). Built 

in sidetone. 

Transmit ter-SSB input: 550 watts PEP, CW 
input: 360 watts. Carrier suppression -45 db. 
Unwanted sideband suppression, better than 

-55 db. Antenna load impedance, adjustable 
40-100 ohms, Hi-Z microphone input for 

-50/60 db leveL 

Receiver— Sensitivity better than % juV for 

10 db S+N/N ratio. Double action, fast at- 
tack delayed release, audio derived age. Nom- 
inal 1 watt audio output to 8 ohm external 
speaker. 

General— Crystal lattice filter on transmit 
and receive provides 2.1 kHz selectivity with 
1.8:1 shape factor. Audio response 300-2, 
400 Hz at -6 db points on receive and trans- 
mit. Dimensions approximately 7^'* H x 

1 1 ^4" W X 13-3/4" D. Weight approximately 

*^^^^' „:W6AJZ 



DX QUIZ . « . Answers 

Here are the answers to the quiz on page 
38 Score five points for each correct answer. 
75% is very good, 90% is unbelievable. 



Congo 




Republic of 




Repub lie 


TN 


Guinea 


7G1 


Republic of the 




Uganda 


5X5 


Congo 


905 


Rwanda 


9X5 


Mali 


TZ 


Xiger 


5U7 


Central African 




Tanzania 


5H3 


Republic 


TL 


Gabon 


IK 


Senegal 


6W8 


Spanish 




Cabindi 


CR6 


Guinea 


EA0 


FerrtHiido 




Mauritania 


5T 


Poo 


EA0 


Lesotho 


7P8 


Zanzibar 


VQl 


Mozambique 


7S9 


Chad 


XT 


Rots wan a 


CRT 



Novice Antenna 

One of the problems the Novice has is the 
antenna. Many times it is a problem because 
of lack of knowledge, space or funds. Here 
is an 80 meter vertical which solves all the 
problems< 

Most of the parts can be scrounged. You 
will need 17 feet 4 inches of Vi" thin wall 
electrical conduit; a 5 -foot piece of 2x2 inch 
lumber; a 4-foot length of tubing to use as a 
supporting mast; a coil, and some hardware* 

Bolt the conduit to the 2x2, overlapping 
about 2 feet. The top of the loading coil (in 
this case Illumitronics jS^20I0-#16 wire, 2W^ 
diameter, 10 turns per inch) is bolted to the 
conduit and the bottom of the coil is bolted 
to the wood. The supporting mast is then 
bolted to the other end of the 2x2 and sunk 
into the ground. 50 ohm coax is used to feed 
this antenna. The shield of the coax is con- 
nected to the mast, and the center conductor 
is temporarily fitted with an alligator clip for 
ease in tapping the coil* 

Using an swr indicator, tap the coil at the 
point where the lowest swr is found- In my 
case, this was about 23 turns. The swr was 
still about 2:L To bring it down, cut two 
radials *^ wavelength long and connect to the 
point where the coax shield is connected to 
the mast* The radials can be buried. Pruning 
the coax length will also help bring down the 
swr at the transmitter. 



«T 4" 






5' 



STOVt 

fiOLTS' 
(4J ^ 



A 



\ 



y 



JOINING POINT OF CONDUIT 



HOLt 




LARGE 
HOLE 



rJlSTEh£DTO*OOD 



fl" 



GROUftiO 



SURFACE 




*-^M flD 



^^A. 



I 



4* 



TO .<MTft 



t 



Fig. 1. Variable is mounted on the 1%" TV 
mast- 

Now that you are thoroughly confused, 
look at Fig, 1 and you will see the arrange- 
ment. 

Wayne Jinske, WA9SSH 



r 



50 



73 MAGAZINE 



The Super SS 



Clifford Khnert 
520 Division Street 
National City, Calif. 92050 



A Real Life True Adventure Story 



It is Saturday afternoon. I return home 
from work slightly tired, but refreshed in 
the thought of the weekend ahead. It 
doesn't happen often, and I rcaliy look for- 
ward to a little relaxation with my favorite 
hobby. I fee! deep pride to be a member of 
the ARRL, the organization that arranges 
these contests. There is nothing I enjoy 
more than operating my station with the 
best of my speed and skill competing with 
others doing the same. 

To the shack. Check it out. Twenty 
meter beam. Forty meter dipole. I turn on 
the transmitter- Oscillator. Drive. Plate 
tuning. 300 mils. Good. I turn on the re- 
Geiver. Let's see who I clobbered. Nobody 
heard me. Good* Coffee. Pencils. Log. 
Paper. Clock- Check. Let's go. 

1 reach for the receiver dial, the hard 
black knob feels smooth in my fingers. 
Smoothly as velvet the pointer moves up the 
scale. The QRN ebbs and flows like waves 
on the beach, now softly sliding across the 
sand- Up through th^ noise pops a signal. I 
gently nudge the antenna trimmer until the 
rhythmic beat of a steady fist rings clear as a 

bell. 

CQ SS. It's a VE, Must turn the rotor. 
Reach for the control, Click-cHck-cHck- 

uummmh. The lights dim. Pull the leads 
apart. No good. Pull the line cord. 

Slightly despondent, I pace the few 
steps to the door and begin the painful 
ascent up the tower along the wall. With a 
mighty effort 1 pull myself to the roof. The 
sun is down now and a light mist hangs over 
the city softly filtering the strange glow 
from the mercury vapor ligliis on the street. 
Above arches the twenty meter beam like a 
parasol with its elements reaching into the 
darkness. Thin wisps of smoke curl from 
the bottom of the rotor, almost masked by 
the veil of the fog. 

Up the tower. Good thing it's strong. 
Welded it myself. Know it's right. At the 
top. I wrap my legs around the tower and 
grip the boom- Pull. Harder. Gears frozen- 
Pull harder. Crack! Small piece of tower 
hits the roof. Hold tight to boom. Boom 
bending. Crack again. Here conies the ro- 
tator. Metal fatigue. Gotta work on that- 
Falling, Here comes a guy wire. Rotator 
catches. Hanging on. Snap! Cheap guy 



wire. Buy it new ne.xt time. Here comes 
top of tower 

Almost gently the top of the tower ro- 
tates downward, bending at the center and 
picking up speed. Now, nearing the roof, 1 
hold tightly and watch its sickening descent. 
The top of the tower shears off the corner 
of the roof like a knife slicing butter. Now 
I carefully make my way down the remains 
of the tower, nothing but a grotesque tangle 
of twisted metaL 

Wow! Splinters and roofing- Down to 
the ground. Forty meter dipole still OK. 
Shack OK inside. Only slight hole in roof. 
Bandswitch. I call CQ SS. Plate meter pins. 
Lights dim. FinaTs shorted. Power switch. 
Reach inside. Pull shielding off finals. It 
hit me. Wall falling away. Floor hits me. 
Everything black. Feel. Hard tloor Still 
alive* Reach for drawer. Flashlight. 

The small sharp beam of the flashlight 
questioningly probes the darkness, tracing a 
cloud of thick grey smoke. I carefully sort 
through the tangle of wires and unplug the 
transmitter. Painfully, 1 limp outside and re- 
cycle the circuit breaker. 1 force myself 
back and view^ the damage. The power 
switch is welded on by the high current. 
The silicon diodes, now completely ruined, 
are blisteringly hot* Now the receiver once 
again warms up and returns to life. 

QRN. On my frequency. Now calling 
me, A ZL. Pretty good signal. I grasp the 
receiver with both hands. Wires breaking 
off. Over my head. Heavy. Push hard. 
Across the room. Into the wall. Plaster and 
wood splinters. Wow! Tear up ARRL cer- 
tificate. On the floor. 

Once again I make the trip across the 
room. 1 move more slowly now with the 
seething forces inside me subsiding. I gently 
pull the light switch and close the door. I 
stroll toward the house carefully stepping 
over an object in the path. Some smoke 
still diffuses through the hole in the wall 
into the still purity of the night. The sky is 
now perfectly clear with the stars flashing 
like gold setfuins on black velvet. 

Quiet. To the house. Open the door. 
Wife. Stilt awake waiting. Arms around my 
neck. Soft. She speaks. 

"Have a good contest?'* 

Yes. ...WB6BIH 



MAY 1969 



51 



4 




Novel Approach to Feeding 



and Tuning 



the 



Three - Band 



Boomless 



Quad 



Although I learned two codes at age 13, 
one of 13 children on a farm in Wisconsin, 
and received my discharge from the Signal 
Corps in Washingion, D, C, in November 
I^J12, I did not obtain my General license 
unlil March 1948 and my Class A in March 
1950. 

One day 1 worked W3JXH in nearby 
Maryland and was invited to drive the few 
miles to sec a quad antenna, my first. It 
turned out to be a 10-15 two-element 
all-Jivetal job and only a few feet above 
ground, surrounded by buildings and over- 
hanging trees, and enciosed inside a high 
steel fence. The owner claimed fine dx 
contacts. 

I then went about building a 1 5-meter 
ali-metat quad with both elements grounded 
on Ihc upper boom. Although this quad had 
excellent l/B ratio, the band remained dead 
for several days, so the 15-mcter job was 



W. E. Rabenborst, WA4VWY 

17 IS 29th Avenue 

Vero Beach, Fiorida 32960 

Member of the Bar, 

U.S. Supreme Court 

taken down and a 20-meter quad of similar 
type built to take its place. It was initially 
fed at only four feet three inches from the 
ground. The first contact was with K3UIG, a 
*^Government Employee" nine miles across 
town. The QSL which arrived two days later 
bore the name Barry Goldwater, with a 
beautiful color photo of the Nation's Capitol 
building. Other contacts were mostly 
beyond the Mississippi River and Central 
America and, when the band was either just 
opening or closing^ generally quad-antenna 
stations answered. Diamond-shape quads are 
said to have a lower angle of radiation. 
Before leaving Washington, D, C, I gave this 
quad to W3YAE. 

After arriving in Florida I decided to 
experiment with quads of the more conven- 
tional square, all wire type. Twelve different 
quads were built and torn down - boom, 
short boom and boomless. No. 13, the 




Nylon cord keeps spacing for 52 ohms impedance when up a/2. 



52 



73 MAGAZINE 



present one, a boomless quad, was designed 
by W4TZ, across town, who had two com- 
posite aluminum spiders electrically welded, 
one of which was assembled and erected on 
the tower by me (age 76) without any help 
and without use of a safety belt. The 
decision not to use the safety belt loaned by 
W4TZ may sound a bit queer. Some 65 or 
70 years ago a group at a Wisconsin family 
reunion witnessed a dog attempting to scale 
a picket gate, as he had done many times 
before. He caught the ring of his collar on a 
picket and hung there helplessly. Hanging by 
a safety belt, should my foot slip, might 
temporarily knock the breath out of an old 
man! However, I strongly recommend the 
use of safety belt, especially to you younger 
fellows with still many years ahead of you. 

The accompanying photo shows the com- 
posite spider to have an aluminum plate at 
the center with eight short aluminum radials 
electrically welded thereto at an angle so 
that the spacing between the 20-meter 
driven element and its reflector is 6 feet 10 
inches, with a corresponding lesser spacing 
for the 15- and lO-mcter elements. This 
spacing, with the reflector properly tuned at 
a sufficient height above ground, resulted in 
a unity SWR when fed with RG/8-U or 
RG/58-U. The Quad handbook says that if 
the quad is below a certain height the 
impedance drops to one-halL 

Square quads are normally fed at the 
center of the lower horizontal wire of the 
driven element. Since dipoles fed at the 
center are said to be a reasonably good 
match for 72-ohm feeders, and an inverted 
**V'* having a 90-degree angle is said to be a 
good match for 52-ohm RG/8-U, I chose to 
feed my square, boomless quad at one lower 
corner for the following additional reasons: 
l)the feeder may be fastened to the radial* 
thereby lessening sway in wind; 2) no need 
to pull the center of the driven element 
upward, out of shape and out of true with 
the reflector; and 3) it seemed to be more 
convenient to attach the SWR bridge at this 
point during tuning procedure. Believe it or 
not, it worked! 

Fig. 1 shows construction of tuning coil 
at the corresponding (but opposite) corner 
of the reflector Note the absence of long 
tuning '^stubs'* in the photo, which not only 
distort the plane at the current node, but 
also tend to affect the adjacent bands. The 
tuning coil was formed by winding antenna 
wire on a 7/8-inch dowfel and, when released, 
forms approximately a one-inch diameter 




Fig, 1, Tuning Coil. When SWR bridge ap- 
proaches unit, the clip A is removed and 
the short lead soldered to the lu i n, A change 
in capacity and configuration of coil might 
affect SWR if the shorted portion of coil 
were to be rennoved, more so, on 10 meters 
than on 20 and 1 5. Less turns are needed on 
1 5 and 10 meters. 

coil. This coil was then spread shghtly and 
fastened to the ends of a somewiiat shorter, 
thin insulator so that the outer edges of the 
turns are spread sufficiently to perniit 
chpping a short piece of wire to a single turn 
without shorting an adjacent turn. Although 
less turns are needed tor 20 meters, I 
started with a 26-turn coil because of 
the length of the insulator on hand and 
made the initial tap at the center turn, 
thereby shorting out one half of the coiL 

Tuning was accomplished with a low 
power SWR bridge at the feed point where it 
could be clearly read at that short distance^ 
and at a time when the band appeared to be 
dead or "out** so as to reduce chances of 
interference. Remember, I had no assistance 
and had to ascend and descend the ladder 
and tower (more than once!) to accomplish 
the tuning. A short piece of vinyl from the 
coax had previously been slipped over the 
clip to prevent rf bum when changing taps 
on coif The coil being at the radial, it was 
easy to steady it during the tuning process 
by grasping the radial with the other hand. It 
was only necessary to go a turn or two either 
side of the original tap to arrive at the 
desired swr. The clip was then removed and 
the wire soldered in place, a 50-foot exten- 
sion cord having furnished the required 
power for soldering gun. After removing the 
bridge and replacing it near the rig, it was 
only necessary to make a twofoot change in 
the feeder length to secure a like SWR 
reading of 1 to 1 at that location. 

I used a 3-cent, home-made balun. fol- 
lowing the general instructions for a 1 to I 
balun in August 1964 QST. The core is 
about 2 inches of ferrite obtained from a 
discarded BC loopstick, and wound with the 
necessary turns of No. 16 copper enamelled 
wire. It is not sealed, but merely taped. 
Weather? Reports from contacts do not 
materially differ, whether during dry 
weather or rain. 

W4TZ uses a common feeder for the 
three bands, and a quarter* wave sleeve balun 



• 



MAY 1969 



53 



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at each of the respective feed points, and the 
other ends of the quarter wave fastened to 
the common feeder. His watt- meter shows 
remarkably satisfactory swr 

Incidentally, either bamboo poles or 
fiber-glass radials may be slipped into the 
short, slotted aluminum arms of the spider 
and a non-skid hose clamp secures the radiaL 

The width of the tower shown in the 
photo was such that only one foot could be 
placed at a time on any cross-member, The 
other leg and one arm were draped around 
the tower during the erection of the quad, 
and the free hand was used to put the thing 
in place. The necessary tools had previously 
been placed in accessible pockets. The tower 
was not of the tilt type. 

If an old man can assemble, erect and 
tune this boomless three-band quad without 
assistance, you younger fellers should be 
able to obtain similar satisfactory results. 

Recently a station reported an S-8 signal 
off the back of the quad, but 20 over S-9 
from the front. Not bad ! 

It is understood that fiber-glass radials 
now come in four-foot sections whose ends 
slip readily into each other^ and are mailable 
by parcel post. At this point it may be of 
interest that I and my supervisor inaugurated 
the Parcel Post System in 1913 after trials at 
Chicago, St- Louis and New York to obtain 
size, weight and cost data. 

If and when I can secure an aluminum 
welder (electric), I may be able to furnish 
this composite spider (and radials). That, 
however, was not the intended goal when 
this No, 13 boomless quad was designed. 

Acknowledgement is hereby made to 
W4TZ for his assistance in designing the 
angle of the spider and having the first two 
prototypes made; also to C. D. Bently for 
photograph, 

. . . WA4VWY 

Mosley 80M Dipole Kit 

The DlV-80 Dipole antenna is a complete 
package designed as a regular or inverted vee 
dipole for 80-1 OM. It is rated at 2 KW 
PEP or 1 KW on AM or CW, The Kit incl- 
udes 140* of Copperweld wire, a Mosley Di- 
pole Connector (DPC4) and two ceramic 
end insulators. The Kit includes simple in- 
structions for pruning the antenna to the cch 
rect length for the part of the band in which 
operation is desired. It might be worth a 
mention that many stations using inverted 
vee antennas on 80 meters are working DX 
with ease. 



54 



73 MAGAZINE 



p 



*fep- 



HOWARD W. SAMS 

Famous Editors & Engineers Books 



NEW AND IMPORTANT 

73 Dipole and Long-Wire Antennas 

by Edward Af. Nolf. The first compendium 
of virtually every type of wire antenna 
used by amateurs. Includes dimensions, 
configurations, and construction data for 
73 types, plus appendices describing 
construction and operation of noise 
bridges and antenna line tuners, and data 
on measuring resonant frequency, veloc- 
ity factor, and SWR. 160 pages. 

65071, only $4,50 

Amateur Tests and Measurements 

by Louis M. DezetteJ, W5REZ, Shows how 
to perform virtually all performance tests 
on amateur transmitters, receivers, and 
antennas, and how to make required ad- 
justments. An invaluable book for the 
amateur who wants to maintain top op- 
erating efficiency. 192 pages. 

65072, only $4.95 



17TH EDITION OF THE FAMOUS E & E 



Radio Handbook 



Tells how to design, buWd, and 
operate latest types of ama- 
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Provides extensive, simplified 
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Thi VHF Amateur 

by Robert M. Brown, K2ZSQfW9HBF. Completely up- 
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to both ofd and new vhf men. 160 pages. 



Commercial RadiatelephoEie License 
Q&A Study Guide 

by Woodrow Smith & Rot&rt Wefborit. Invaluable prep- 
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are detailed and comprehensive. 272 pages. 

031f oniy. . , . , , * - , , - . $6 J5 



Single Sideband: Theory and Practice 

by Harry 0. Hooton, W6TYH, The one-source guide to 
ssb, covering origin and principles* derivation of ssb 
signals, carrier-suppression techniques, sideband se- 
Jection, and a complete analysis of ssb equipment. 388 
pages. EE-aso^ only. , $6.95 



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by Donald L Stone r, W6TNS & Lester A. Earnshaw, 
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struction projects for solid-state equipment 180 pages. 
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by Robert M. Brown, K2ZSQ/W9HBF and Tom Kneltel, 
K2AES. Fully explains the new incentive licensing 
which affects both newcomers and old-timers. Covers 
all the new FCC H^gulations and band allocations. 
Includes sample exams for Novice. Technician, Con- 
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sing. 160 pages. EE-050, only. «*.««. « . t . . .$2.75 



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by Howard S. Py/e, W70E. Provides all the information 
you need lo obtain your advanced— or extra-class 
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sample questions for each exam. 192 pages. 
20649. only , $3.95 

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by Howard S, Pyle, WIDE, A complete guide, including 
typical FCC test questions and answers, to help you 
prepare for the Technician, Conditional, or General- 
Class radio exam. 144 pages. 20639, only,., $3»25 

Amateur Radio SSB Guide 

by Harry D. Hooion. Invaluable to anyone owning or 
planning to buy ssb equipment. Explains basic princi- 
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I HOWARD W. SAMS « CO., INC. 

( Order from any Electronic Parts Distributor, or 
I mail to Howard W. Sams & Co., inc., Dept, 73-5 
4300 W. 62nd St., Indianapolis, Ind. 46268 

) Send the following books: Nos 

I 

- S enclosed 

r 

I O Send FREE 1969 Sams Book Gatatog 

' Kama _ 

I PLEASE PRINT 

J Address ^ 

I City ^State Zip 

I 



. 



J 



^ 



I 



To Patch 



or 



Not 



To 




For 20 years, hams have argued about 
phone patches. After a generation of dis- 
cussion, the matter is about to be settled. 
The phone patch may become another "stan- 
dard" appliance in the ham shack- But not 
without some trials and tribulations, 

The idea of the phone patch is almost as 
old as the radio and the telephone. Military 
services have used ''radio-wire integration," 
and the phone companies have long distance 
radio links. Telephones in private automo- 
biles are obviously phone patches. Amateur 
equipment has included phone patches for 
years, too. A number of respected compan- 
ies make them, and articles have appeared 
from time to time in CQ and 73 magazines. 
Why, then, is there so much confusion? The 
problems and arguments start with the "tar- 
iffs" filed by the telephone companies. For 
most practical purposes, a tariff can be con- 
sidered as a law. Almost every telephone 
book prints a tariff which bothers the ama- 
teur with a phone patch "No equipment, 
apparatus, circuit or device not furnished by 
the telephone company shall be attached to 
or connected with the facilities furnished by 
the telephone company-,./' The arguments 
caused by this tariff are shown by the atti- 
tudesof the amateur radio magazines and the 
ARRL* CQ magazine has continued to print 
phone patch articles, 73 magazine has been 
rejecting articles until a decision is made by 
FCC And the ARRL has maintained the 
opinion that all phone patches are illegal. 
There is no mention of phone patches in 
'The Radio Amateur's Handbook/' and the 
only mention of telephones warns the ama- 
teur to contact the telephone company if 
telephone interference occurs. 

The official attitude of the telephone com- 
panies has been that phone patches were not 
legal. As a practical matter, though, ''Mother 
Belf has realized that amateur use of phone 
patches actually increases telephone traffic. 
Of course, there were objections if the ama- 
teur tried to connect his own extension 
phone in the shack and to install the wiring 
himself (thus avoiding extension phone char- 
ges). Poorly designed or operated patches 
have sometimes l though seldom) brought a 
knock on the door. But as a practical mat- 



Dale E. Coy, W5LHC 

3322 49ib Loop 

Sandia Base, New Mexico 87116 

ter, the ham who asks the phone company to 
install an extension phone in the ham shack 
has usually found that the phone installer is 
quite willing to assist in hooking up the 
phone patch. At least, that way, it is done 
correctly. The fact is that hams have rarely 
(if ever) been prosecuted for operating a good 
phone patch. 

The possibility has always existed, though, 
that the amateur might be doing something 
illegal. This possibility has resulted in a 
great reluctance to use phone patches. Some 
recent decisions of the FCC may change the 
tariffs, and could result in expanded use of 
the phone patch. 

The FCCcan.if it wishes, review telephone 
company tariffs and set aside those tariffs it 
does not approve. In 1956, the FCC's 
**^Hush-A"Phone" decision caused a clarifica- 
tion of tariffs to allow use of devices which 
are not electrically connected to the phone. 
The legal wording of the decision caused 
many lawyers to feel that amateur phone pat- 
ches would also be considered legal, although 
they are usually connected to the phone 
lines. After 12 years, in June, 1968, the FCC 
has clarified its position in a decision on the 
**Carterfone" case. The most significant 
portions of the FCC opinion are printed be- 
low. 

We hold that the tariff is unreasonable in 
that it prohibits the use of inter-connecting 
devices which do not adversely affect the 
telephone system,.-. Our conctuston here is 
that a customer desiring to use an inter* 
connecling device to itnprove the uiilify to 
hiin of both tiie telephone system und a 
private radio system should be able to do so 
so long as the inter-conncction does not ad- 
vcrsely affect the telephone company \ oj> 
crations or the telephone system's utility 
for others, A Tariff which prevents this is 
unreasonable, .,AVe are not holdinu t!iat the 
telephone companies may not prevent the 
use of devices which actually eause harm or 
that they may not set up reasonable stan- 
dards to be met by inter-conncction devices. 
These remedies are appropriate. Wc believe 
I hey are also adequate to fully protect I he 
svstem. 

m 

The opinion set aside Ihc tariffs prevent- 
ing connections to the telephone system, and 



56 



73 MAGAZINE 



declared that they ''are and have since their 
inception been unreasonable, unlawful, and 
unreasonably discriminatory,./* The "Car- 
terfone" decision, then, declares that phone 
patches are (and have always been) legal, if 
they do not harm the telephone equipment- 

This decision, and tariffs effective January 
1, 1969, (more on this later) have caused the 
ARRL to change its mind and allow phone 
patches as "legal'' traffic. But, as might be 
expected, the telephone company does not 
appreciate the FCC decision. *'Mother Bell" 
will lose a lot of money if customers go else- 
where for Teletype interface^ facsimile, and 
data transmission equipment. The telephone 
company has appealed the decision— or at 
least a part of it— in a New York appeals 
court- This action is mostly intended to pre- 
vent suits by Carter and others, and doesn^t 
appear to be intended to overturn the entire 
FCC decision. 

It seems that AT&T intends to get the 
most mileage from the part of the FCC de- 
cision which says "We are not holding that 
the telephone companies may not prevent 
the use of devices which actually cause harm 
or... set up reasonable standards to be met../' 
Under this part of the decision, AT&T could 
file a tariff requiring inspection and approval 
of any connected device (including phone 
patches) by the local telephone company. 
This procedure has been in effect for some 
time to allow customer use of the customer*s 
own telephone instrument as an extension. 
Inspection of the extra or "decorator" 
phones often costs $10 or more. Checking 
a phone patch would probably cost so much, 
or take so much paperwork, that the average 
ham wouldn't bother 

The move which prompted ARRL's accep- 
tance of phone patches was the AT&T tariff 
(FCC) Number 263, which was effective Jan- 
uary 1, 1969- This tariff has, in turn, been 
"reproduced'* by the telephone operating 
companies and filed with state regulating ag- 
encies- The provisions quoted below are 
from Mountain States Telephone and Tele- 
graph Co. General Exchange Tariff for New 
Mexico, Section 17, Part 12, effective Janu- 
ary 6, 1969. The FCC tariff, and other local 
tariffs, are almost identical. 

Connection with customer-provided Eqiiip- 
ment and Facilities. ...Certain customer-pro- 
vided voice transmitting and/or receiving 
terminal equipment may be connected to the 
Exchange and Long Distance Message Tele- 
communications networks at the regula- 
tions, rates, and charges specified herein. 
...May be connected through a Telephone 



Company network control signaling unit at 
the following rates and charges: Connecting 
arrangement, for connection of customer- 
provided voice transmitting and /or receiving 
equipment (including switchhook control 
key), each (OKT) $ ,50 month ly* Mainten- 
ance service call resulting front customer- 
provided equipment, each SIO. 

This ''QKT'' connecting arrangement is 
rather simple. The '"network control signal- 
ing unit" is a slightly-modified telephone in- 
strument. A special switchhook key is pro- 
vided. One of the buttons in the telephone 
cradle may be lifted and locked into place, 
which will cut out the telephone transmitter 
element and switch in a special set of coOs 
hooked to the ^^QKT" jack. 

The Electronic Industries Association has 
called the "network control signaling unit" 
provision of the tariff '*common carrier 
featherbedding." The provision means that 
the customer cannot provide his own means 
of dialing, impedance matching, or answering 
of calls. While this provision will not bother 
most hams, some of us like to provide our 
own dialing arrangements. In addition, no 
matter how good your patch is technically, 
even if it is better than telephone company 
equipment (and many are), the company 
won't trust it. 

The 50 cent monthly charge seems reason- 
able, although it does add up to $6 a year. 
Of course, a one-time installation charge is 
added (about $6.50), as well as the monthly 
cost for the extension phone if the one in the 
shack isn't the only one in the house. 

The '"maintenance service calF' provision 
of the tariff means that any trouble caused 
by your phone patch will cost you $10. If 
you complain about your telephone service, 
and the cause is really your patch, it^s your 
$10. If it's the fault of the telephone comp- 
any, there is no charge. And, of course, if 
your patch causes problems which bring an 
unasked-for knock at the door, this will also 
cost you. 

The "QKT'' jack provides access to a 900- 
ohm matching coil within the telephone. For 
phone-patch purposes, you can treat this just 
like a telephone line, except that you cannot 
use it for dialing, and you cannot **answer'' 
or "hang up'^ using this line. The 900-ohm 
figure probably comes as a surprise to you, 
as it did to me. For years, we have been 
thinking that line impedance was 600 ohms, 
and carefully designing our patches to work 
into that figure. The old, open-wire telephone 
lines were 600 ohms. It came as a great 
shock to me to learn that almost every sub- 



MAY 1969 



57 




scriber line in the United States now has a 
nominal 900'ohm impedance. This fact will 
probably be a surprise to most phone patch 
manufacturers, also. However, the 600-ohm 
equipment has worked well in the past. 
There are other restrictions on what you 
can feed to the jack supplied by the telephone 
company. 

..-Power of the signal at the central office 
(must) not exceed 12 db below 1 milliwatt 
averaged over any 3 second interval..,, The 
power of the signal which may be applied by 
the customer-provided equipment to the 
Telephone Company interface located on the 
customer's premises will be specified for each 
type of connecting arrangement but in no 
case shall it exceed one milliwatt. 

In other words, you are not allowed to 
over-drive the telephone company lines. This 
is a reasonable provision, and should be the 
basis for providing a meter on your phone 
patch, although most patches don't have me- 
ters. It is not too likely that your patch will 
provide more than a legal signal- If it does, 
the "network control signaling unit'* has 
some built-in compensation- Of course, the 
telephone company could specify an un- 
reasonably low input leveL Line loss can be 
as high as 10 db. Be suspicious in this area, 
but don't leave yourself open to that $10 
charge. 

The power in the band 3995 to 4005 Hertz 
shall be at least 18 db below the limit (that 
is, 18 db below the 12 db below 1 milliwatt 
at the central office)-, -The power in the 
band 4,000 Hertz to 10,000 Hertz shall not 
exceed 16 db below 1 milliwatt... -10,000 
Hertz to 25,000 Hertz-24 db below.,. 
25.000 Hertz to 40,000 Hertz- 36 db below 
...above 40,000 Hertz-50 db bclow,,. 

These figures give the "low-pass" filter 
requirements which your phone patch must 
meet. They should not cause any difficulty. 

To prevent interniption..,(the) signal (will) 
at no time have energy solely in the 2450 to 
2750 Hertz band. If signal power is in (the) 
band, it must not exceed the power present 
at the same time in the 800 to 2450 Hertz 
band. 

This rather simple restriction is the reason 
for the occasional unexplained disconnection 
of an apparently-good phone-patch circuit. 
The telephone companies use special signals 
in the 2450-2750 band which are the equiva- 
lent of a "hang up" command, and the call is 
cut off. An occasional hetrodyne at the 
wrong frequency can cause this problem, but 
there is not much you can do about it. 
Other Methods 

There is one other way to accomplish a 
phone patch, and it can be done at a saving. 



Section 20 of the tariff provides restrictions 
on "Inductive or Acoustic Coupline," whicli 
can be used without charge* I suspect that 
there will be quite a bit of amateur develop- 
ment effort toward developing inductive or 
acoustic phone patches. The restrictions are 
as follows: "...Network control signaling shall 
be performed by equipment furnished, in- 
stalled, and maintained by the Telephone 
Company* 

In other words, you have to have a tele- 
phone* No fair just inductively coupling the 
patch to the telephone company lines. 
"-..Connection is made externally to a Tele- 
phone Company network control signaling 
unit," 

You can't put part of the patch inside the 
telephone. The inductive coupler or acous- 
tic arrangement must be outside the phone* 

...Equipment must comply with the follow- 
ing minim urn network protection criteria: 
...The power of the signal which is applied 
by the customer-provided equipment to the 
network control sfgnaUng unit located on the 
customer's premises be limited so that the 
signal power at the output of the network 
control signahng unit (i.e. at the input to the 
telephone company line) does not exceed 9 
db below 1 milliwatt when averaged over 
any three second interval. ...(and). ...(frequen- 
cy /power limits). 

Notice that the signal power restriction is 
9 db below 1 mw at the line input, rather 
than at the central office. If your line hap- 
pens to be among the worst, your signal could 
be 19 db down at the central office, rather 
than the 12 db allowed for an electrically 
(QKT) connected system. This is rather re- 
strictive, and again industry has objected. The 
frequency/power limits are the same as 
listed before, except that they are referred to 
the minus 9 db figure- 
Now What? 

With phone patches now legal, the ama- 
teur ^'fraternity'' should take some positive 
action. Each of us with a phone patch must 
make sure that the patch is operated properly 
and that it is not harming the telephone e- 
quipment. 

Since a tariff now exists for customer- 
provided equipment, the telephone com- 
panies can no longer turn a blind eye on 
phone patches. The cost is really very reas- 
onable, and the peace of mind is worth it. 
Call the local company and get "legal" your- 
self. 

Since the ARRL now recognizes phone 
patches, we should urge the ARRL and any 
other interested amateur groups to present 
the amateur views on this subject to the FCC 



58 



73 MAGAZINE 



and the state regulating agencies. I feel that 
a well-designed phone patch should not be 
subjected to the additional restrictions of a 
"network control signaling unit," and should 
be allowed to provide diaUng, answering^ and 
control functions if properly constructed. If 
you support this view, write the ARRL, The 
FCC sometimes listens to the voice of ama- 
teur radio. Possibly, a good quality phone 
patch could be used as a supporting exhibit- 
In any case, make your opinions known. 
The phone patch is a useful piece of equip- 
ment, and now it*s legaL Let's keep it that 
way- 

.,,W5LHG 



Will Amateur Radio 
Win the Technology Race? 

Ham radio is becoming extremely techni- 
cal, what with SSB, VHF, UHF, SHF, Moon- 
bounce, Pulse, MaserSj Lasers ^ etc. Unless 
the convictions of most amateur radio opera- 
tors change drastically, technology may des- 
troy ham radio • 

As an 18-year old electronics engineering 
student, I have been observing the more ex- 
perienced operators above the age of thirty, 
most of whom have beconie content to pos- 
sess their general license and just chew the 
rag. Few will admit their stagnation, but 
only a handful of ''go-getters" are advancing 
ham radio technically. And even fewer are 
keeping up with the advancement • Many SSB 
operators really do not even understand the 
technique of SSB generation! 

Just take a look at the bands above 50 
MHz. Only on the frequencies where com- 
mercial equipment is available are there any 
large-scale operations. The majority of ham 
radio is not willing to explore the upper re- 
gion, either due to lack of knowledge or lack 
of mjtiative. 

Now I am not professing to be an elec- 
tronics genius, but I am not content to pass 
the test and fake a rest! After four to eight 
years of college, I plan extensive study of ra- 
dio technology, far beyond what is expected 
of the average ham. 

What I am advocating, however, is not for 
all amateurs to study college courses. This is 
too much to expect. But at least be able to 
understand your present lig. Try to keep 
pace with the moderate theory- Maybe, if 
you keep active, both on electronics theory 
and on the air, you*ll be a better ham. Re- 
member, amateur radio is not CB. We are sup- 
posed to lead in technology and experimen- 
tation, not follow, 

Roy C, PoUitt, WA3IID 



TOROID CORES 



Red "E" Cores*500 kHi 
to 30 MHz- ;t = 10 



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T-50^2 




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T-37-2 




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.09 


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T-12-2 




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Yellow 


"SF" 


Cores- fO MHi 






to 90 


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fi = 8 








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fo 200 MHi 


= 7 








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With Spec 



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dreds of practical apphcatlons.r $1.50 

MINIMUM ORDER: $1.00 

Please Add 25$ per order 

for Packing & SKipping 

AMIDON ASSOCIATES 

T2033 Otsego Street 
North Hollywood, Colif. 91607 




C4MP ALBERT BUTLER INVITES 

HAM RADIO ENHUSiASTS OF ALL AGES 

TO TRY FOR YOUR 
GENERAL CLASS TICKET 

THIS SUMMER! OUR 8th SEASON 

NOVICES, TECHNICIANS AND C.B/ers 
ESFECIALU TAKE NOTE 

Ttill co-ed Amateur Radio Camp, Y.M.C.A. owned and operated, 
can accommodate GO campers. There 1ft no age limit. W& have 
hftd campers from 7 through 14 years of age. It la vtry belpful If 
Tou etti copy 5wpm ^r hare a Nof ice or Technician tlcketp but It 
Ifi not necessary. Time U divided between radio claaiei In code 
And theory and the uatial camp acthitka. sucli as swimming, 
archery, tifferr, hlklnit. etc. Golf prUlIeges are Included it the 
beautiful New River Country Club course, 

Entira staff consists of licensed hams who are lnfttru€t4>ri In 
electrical enflJieerln^ In some of our finest colleges and unlFer- 
eitias. Camp opena August 2 and closes August 16th. Tuition of 
S185. 00 Includes all carap expenses: rooni^ meaUi notebookt, text- 
books, and insurance. Send for our brochure. 



I C. L. Peters, K4DNJ 

' Ggnsral Secretary 

I Gilviii Rotfi Y.M.C.A., Efkrn, North Corolina 

I Pl0a9a tend me the Booltlet and Application Blank for the 
Cicap Albert Butler Badio Seitlon. 



NABfE 

C A Xj U w»m 

ADDRESS 

CITY 



if«IF4«i.»i. *^¥ ¥■*«*■■■ VBV'CKB Ait wvA'ilf^tpvv + ll'* 4 i#B-^**#'*. 



> * « #■ *«•« * « v***v* ■ ■ i-t i 



!'#•'* Hi •**«<«*■ 1 « *•• «Bf #>■•■« >■ ■ B I 



l*****m**m 



■ « ■«• t *'»1'1'*«« 1 1 



[ 

I 



»•««••*••« 



STATE _ ZIP 



•****«•« f4#4 



.r 



MAY 1969 



59 



mm 



-n 




Direct - Reading 
SWR Indicator 



J.M.Ptosm\ K3V/RV/ 

P, O. Box 68 

New Market, Maryland 21774 




The direct reading swr indicator. 

The device described here was conceived 
as a result of my somewhat frustrating ex- 
perience in tuning an antenna matching cir- 
cuit. The procedure usually recommended 
goes something like the following: 

1. Tune up the transmitter into a dummy 
load of the proper impedance, 

2. Remove the dummy load and connect 
the antenna matching unit to the transmitter 
through the SWR bridge. 

3. With SWR bridge set to forward 
(FWD) position and transmitter energized, 
set the meter pointer to full scale. 

4. Switch the SWR bridge to reflected 
(REF) position, and adjust antenna match- 
ing unit for minimum reading on the meter. 

This sounds simple enough, but all too 
often the REF reading is decreasing because 
the transmitter out'^ut is decreasing as a re- 
sult of mismatch, lo guard against such a 
condition^^ter an adjustment is made, the 
SWR bridge must be set to FWD, the meter 
adjusted to full scale, and the SWR bridge 
again switched to REF. Hopefully, the SW^R 
has been decreased, but this is not always the 
case. What is involved, then, is a repetitive 
cycle of setting the meter to full scale in the 
FWD position, switching the bridge to REF. 



making an adjustment to decrease tlie read- 
ing, and then checking the result. This can 
get pretty frustrating after a while. There 
should be an easier way, and there is. 

What is needed is a way to compare the 
forward and reflected readings continuously 
while making the adjustments to the match- 
ing unit. Of course this could be done by 
using two meters to show forward and re- 
flected power simultaneously, and adjusting 
everything to maximize the reading on the 
forward meter while minimizing the reading 
on the reflected meter, I feel that the device 
dcsciibcd here is even simpler to use and it 
requires only one meter. Basically, it is a 
voltage comparator, as shown in Fig. 1. The 
meter should have a high impedance for best 
results. This circuit has some limitations, 



FWD 

Q 



REF 
0- 



iOk 



lOK 




yon 



Fig, 1. A simple voltage comparator. This 
circuit has some limitations since 3 false ^wr 

reading may resuft depending on pov^^er. 

For example, there is no way to determine 
what the SWR is; that is, high power with 
high SWR may give the same reading as low- 
er power with low SWR, This limitation is 
removed in the circuit of Fig. 2. Ihe SWR 
calibrations on the usual SWR indicator are 
computed from the following equation: 
SWR = (FWD + REF) / {FWD RFFK As 
an example, if we let !0 represent a full 
scale reading, and adjust to full scale with 
the bridge set to FWD, and switch to RI F 
and get a hiilf-scale reading (5) the SWR is 
(10 +5)/ (10 5)^3,0. For the same case. 
using the circuit of Fig. 2, the voltage al 
point F will be twice that at point R, If we 
now set Rl to its midpoint, the meter will 
read zero, it now becomes obvious that Rl 



60 



73 MAGAZINE 



f *D 



REF 



lOK 



lOK 



iO 






^<5> 



J 



lOK 



Fi§. 2, The direct reading swr indicator 
which gives more accurate resufts. 



can be equipped with a dial calibrated in 
SWR; i.e., the midpoint would correspond to 
SWR = 3,0, The dial can be calibrated by 
use of an ohnimeter as follows: 

Resistance (from 
SWR ground end) 



1.0 





1.2 


909 


1.5 


2000 


2.0 


3333 


3.0 


5000 


5.0 


6667 


10.0 


8182 


20.0 


9048 


00 


10000 



The meter used in my version is a 1 MA 
movement with a transistor amplifier similar 
to that described in January 1966 issue of 
73. The meter arftplifier was built on an 
etched circuit board for mounting directly to 
the meter terminals. The meter scale is arbi- 
trarily calibrated with zero in the center. A 
resistor (82K) is used in series with the base 
lead to prevent changes in the zero-set when 
Rl is varied- My bridge has a positive out- 
put. If the one to be used has a negative out- 
put, the meter should, of course, be reversed. 

The use of this device is extremely simple. 
The transmitter is first tuned up using the 
du*iimy load. The antenna matching unit is 
then connected to the transmitter through 
the SWR bridge. The meter is set to zero, 
and the transmitter is then energized- Ad- 
justing Rl to bring the meter back to zero 
will then enable the SWR to be read from 
RTs dial- After this, any adjustment of the 
antenna matching unit which causes a more 
positive meter reading on the SWR indicator 
is in the right direction. The amount of in- 
crease in meter reading is a relative matter, 
depending not only on the SWR but also on 
the transmitter power. If the operator de- 
sires to determine the new (improved) SWR, 
he need only adjust Rl to bring the meter 
back to zero and read off the SWR from the 
calibrated dial. 

Of course, the use of the direct-reading 



v^< 



Usten for the hundreds of 
LK-20O0 lineors now on the 
oir ond judge for yourself. 
Wrire for free iltustroteei 
brochure or send $1 .00 for 
technical and instruction 
manucil. 



Ill AMATEUfi DIVISION 



BTI LK-2000 

UNEAR 
AMPLIFIER 

For SSB, CW, RTTY 

Maximun legal input 
Full loading 80-10M 
Rugged Eimac 3-1000Z 
Dependable operation 
Ea$y to load and tune 
No flat topping with ALC 
Distinguished console 

Instant transmit 

High efficiency circuit 

Designed for safety 

Fast band switching 

Real signal impact 

Price .... *79500 

READY TO OP£RAT£t 



Haf Strom Technical Products 

4616 Santa Fe , San Diego, Ca* 92109 




A look at the interior. Obviously a simple 
device to build. 

SWR indicator is not Uinited to tuning an- 
tenna matching networks. It can be used by 
anyone who would prefer its simplified SWR 
readout. If Rl is set to a higher SWR than 
that actually existing, a positive meter read- 
ing results, and the transmitter can be tuned 
for maximum output by maximizing the 
reading, just as in using the conventional in- 
dicator in the FWD position. .„K3 WRW 



MAY 1969 



61 



H 



Asymmetrically Feeding 

Long - Wire Antennas 



John J. Schuitz, W2EEY/1 

40 Rossie Street 

Mystic, Connecticut 06355 



Changing the location of the feed-point on 
long-wire antennas can make major changes 
in the radiation pattern -changes that can be 
used advantageously when the antenna place- 
ment must remain fixed. 

Illustrative patterns and methods to match 
and determine the feed point impedance are 
presented. 

Many amateurs have room enough to erect 
an antenna that runs only in a specific direc- 
tion. This situation may be due to points 
being available to support the antenna in only 
specific locations, or an antenna may have to 
be run in a specific direction because of ob- 
stacles, safety requirements, etc. When a 
wire antenna (doublet feed with a coaxial or 
a resonant line) is used on the lower frequen- 
cy bands, the height in wavelengths is norm- 
ally not very great, and the antenna radiation 
pattern is very broad -such that stations can 
almost be worked equally well whether sit- 
uated '^broadside'* or *'off the ends" of the 
antenna. On higher frequency bands, how- 
ever, due to the increased electrical height 
and length of the antenna, the radiation pat- 
tern becomes quite sharp, both in the hori- 
zontal and vertical planes. On bands such as 
20 meters and lower, one may have room 
enough to run an antenna that is several wave* 
lengths long. But, if the line of the antenna 
must He in a direction that coincides with 
the direction to a desired area, the signal 
radiated to that area will be many db below 
what it would be if a simple Vi X dipole could 
be erected at right angles to the long antenna^ 

Assuming that one can only run a wire 
antenna in a fixed direction, one has to find 
some means of changing the radiation pattern 
to favor a desired area other than that of 
physically reorienting the antenna. One 
method that can be used is to asymmetrically 
feed the antenna. There is some change in 
radiation pattern when a wire antenna is ei- 
ther center or end fed, but the change is not 
extremely great (when end-fed, the radiation 
lends to he emphasized towards the unfed 



end). However, asymmetrically feeding a 
long antenna can produce a variety of tail- 
ored radiation patterns. One can't complet- 
ely rotate the radiation pattern to any desired 
direction, but it is possible to at least develop 
useful radiation in directions that aren't cov- 
ered by a symmetrically fed antenna or to 
produce a reduction in the response of the 
antenna towards a direction from which in- 
terference originates. 

Effect of Asymmetrical Feed 

The horizontal radiation pattern of a hor- 
izontally placed wire antenna is determined 
by the current/phase relationships in various 
sections of the antenna. When the antenna is 
symmetrically fed, a symmetrical horizontal 
radiation pattern results, such as is shown in 
Fig- 1- The cloverleaf-type pattern shown in 
Fig. 1 results whenever the total antenna 
length is more than about 3/4 X ; otherwise, 
the main radiation is broadside to the Une of 
the antenna. As the antenna is made longer 
in terms of wavelength, the lobes of the 
cloverleaf pattern become sharper and have a 
peak intensity at an angle closer to the line of 
the antenna. Sharp secondary responses also 
appear, some of which can have the radiated 
intensity of a dipole at its maximum orienta- 
tion. 

If one had a 3 X long antenna which prod- 
uced the horizontal radiation pattern shown 
by the solid line in Fig. 1 and found that this 
pattern produced poor results in certain dir- 
ections. Fig. 2 shows some of the solutions 



ir 



( 1 A h 




1/ 



f 3 U 

Fig. 1, The horizontal pattern of a T A long 

svTimetrically fed antenna (dotted linos) and 
a 3a long syn^metrical antenna. 



62 



73 MAGAZINE 






2 A 



-7/^ 



I 1/2 A 



2 f/8 A 



"7/^ 



I 3/8 A 



2 3/8 A 



T/- 



t 1/8 A 






7/^ 



T/" 



"7/^ 



2 1/2 A 



2 3/4 A 



3/4 A 



2 15/(6 A 



9/16 A 





3 A 



7/ 




1/2 A 



3 1/16 A 



7/" 



7/16 A 



3 1/8 A 



7/" 



3/8 A 



Fig. 2. Changes in the horizontal pattern are iUustrated as the total length of an antenna (3%a) is held 
constant, but the feed point is moved gradually toward the right. 



that asymmetrical feed can offer. Note that 
the horizontal patterns in Fig. 2 are produced 
as the total antenna length remains constant 
and the feed point is moved towards the 
right. The same form patterns but with 
mirror responses would be produced if the 
feed point were moved toward the left. 

Particular patterns deserve note, and it 
should be apparent as one studies the dia- 
grams that in some cases very little change is 
required in antenna dimensions to produce 
significant changes in the pattern. 

As the short side of the antenna is de- 
creased slightly in length, some broadening 



of the main lobes occurs and the sharp second- 
responses are more filled in. The peak re- 
sponse of the main lobes changes from about 
20 degrees to 45 degrees as measured from 
the line of the antenna. As the short side is 
reduced to 9/16 X, an almost unidirectional 
type of pattern forms. A further slight re* 
duction in the '"short" side length to Vz X 
produces a pattern that can be very useful in 
many circumstances. Two of the main lobes 
remain quite sharp and produce some gain 
while other main lobes have essentially dis- 
appeared from their usual location, thus leav- 
ing a deep null for about a 60 degrees arc in 



MAY 1969 



63 



1 



one diiection. Other responses produce a fair- 
ly full response broadside to the line of the 
antenna. Such an antenna pattern might be 
useful if one wanted to concentrate radiation 
in an easterly or westerly direction (produc- 
ing a good null in the opposite direction) and 
still have a reasonable amount of north-south 
response. When the "short" side is reduced 
to either 7/16 or 3/8 X, primarily broadside 
radiation takes place. Such a response would 
be ideal for the fellow who moans that he 
can't work anyone in a direction broadside 
to the line of direction of his long-wire anten- 
na- 

The patterns shown are only exactly true 
for a frequency or band where the antenna 
lengths are the electrical lengths shown. They 
do change with frequency. However, as a 
general approximation, they still will retain 
the same general shapes when* for instance, 
the 3X antenna is operated on a frequency 
such that its electrical length is 1 Vik. As the 
total electrical length of the antenna is made 
shorter^ varying the feed point placement 
has less effect upon the horizontal pattern. 
Ft probably is not worthwhile to experiment 
with asymmetrical feed to vary the antenna 
pattern when the antenna electrical length is 
less than IX. 

Feed Point Impedance 

As the feed point is varied, the impedance 
presented will also vary. The range of varia- 
tion depends upon such factors as the anten- 
na element/ wavelength diameter ratio and 
can go from 50 ohms to a few thousand ohms 
with thin- wire antennas. 

One could simply feed the antenna with 
a resonant line such as 450 ohm open wire 
or twinlead and employ an antenna coupler 
at the transmitter end to derive a low impe- 
dance, non-reactive load for the transmitter* 
A transmatch coupler will easily handle the 
range of impedances encountered, for in- 
stance, and provides a handy means for multi- 
band coupling to the antenna. 

For those interested in single band opera- 
tion and/or using a non-resonant feedline, 
the antenna impedance that must be matched 
can be calculated without too much complica- 
tion* To a close degree, the feed point impe- 
dance of an asymmetrically fed antenna is 
one-half the combined impedance of two 
symmetrically fed antennas whose half length 
is equal, respectively, to the length of each 
side of the asymmetrical antenna Some ex- 
amples should make this calculation clear* 

Suppose that an asymmetrically fed an- 
tenna is used having a "short*' side of %X and 



a "long" side of 314X . The feed point impe- 
dance will be one-half the added feed point 
impedances of a symmetrical 'A\ and 6'M 
(13/2X) antenna. The center impedance of a 
V^X antenna is about 70 ohms and that of an 
odd multiple Vih is the same» or also 70 ohms 
for the 13/2X antenna. The combined impe- 
dance is 140 ohms, half of which is simply 
70 ohms— the same as for an ordinary ViX dip- 
ole. In this special case, an ordinary 50 or 
70 ohm coaxial hne can be used to feed the 
antenna directly, with the addition of a 1:1 
balun, if desired, to preserve the feed-point 

balance. 

As another example, slightly more com- 
plex, consider the situation if an asymmetri- 
cal antenna were used having a "short" side of 
3/8X and a 'long" side of 3 1/8X. To find 
the feed -point impedance, it is first necessary 
to determine the feed-point impedance of 
a symmetrical 3/4X and 6^4X antenna. These 
can be determined from the graphs shown in 
Fig, 3* The curve is used which corresponds 
to the wire diameter /wavelength ratio of the 
actual asymmetrical antenna. In this case, a 
X/1000 ratio is assumed, which is slightly 
large for a wire antenna operated on ten me- 
ters, for instance, but close enough to pro- 
duce meaningful results. Then, the center 
impedance of the 3/4X symmetrical antenna 
is found to be about 500 ohms resistive and 
+500 ohms reactive (500 +j500). The center 
impedance of the symmetrical 6^/iX antenna 
cannot be read directly, but since the impe- 
dance values repeat every wavelength, the 
impedance value of the 634X antenna is ap- 
proximately the same as a 1 ^^ or 2 %X antenna* 
From the graphs, the impedance value is 150 

ohms resistive and -500 ohms reactive. The 
center impedance of the asymmetrical anten- 
na is: Z=y2(500+j500+150^j500H/2(650)=325 

ohms. 

In this case, the reactive portions of the 

two symmetrical antennas are equal in mag- 
nitude but opposite in sign, so they simply 
cancel. The resultant resistive 325 ohm feed- 
point impedance would offer a good match to 
a 300 ohm twinlead feedline, or the antenna 
could be fed via a 4:1 balun with 75 ohm 
line, thus taking care of the impedance match- 
ing problem and preserving the feed-point 
balance simultaneously, 

The choice of other **short" and "long" 
lengths for the asymmetrical antenna may 
not, of course, offer such simple feed-point 
impedances. In such a case, one can either 
build a matching network to allow coupling 
to the antenna by a non-resonant feedline or 
accept some slight change in the radiation 



64 



73 MAGAZINE 



•POOO 



(A 

3 
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o 



u 
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til 

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9000 



6000 



7 000 



eoDo 



5000 



4000 — 



iOO? 



.?000 



lOOD — 



iSX 



DEAJUIETER ' 



100000 




5000 J — 



tfl 



5* 



I A t 5K 2. Oh 

TOTAL LENGTH 



25A 



4 000 — 



3000 — 



ZOOO 



3: 
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1000 


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ui 




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TOTAL LENGTH 



201 



2bX 



Fig. 3. Graphs of the feed-point resistive and reactive components of a symmetrical, center feed an- 
tenna. As explained in the text, these graphs can be used to calculate the feed-point impedance of an 
asymmetrical antenna- 



pattern and use the closest **short" and 
"long" lengths which provide a convenient 
feed-point impedance. 

Summary 

So many factors affect antenna directivi- 
ty, both in the horizontal and vertical planes, 
in a given actual installation, that only using 
the antenna can disclose its true performance. 
If, however, a long-wire antenna does exhibit 
dead spots in a particular direction or if it 
is desired to reduce the level of interference 
from a certain direction, asymmetrical feed- 
ing of the antenna offers a possible solution 
with extremely Uttle effort and cost. 

For those who would like to experiment 
and know something of transmission line 
stubswitching.it is possible to develop, using 
the principles presented, a dual feedline an- 
tenna with a selectable pattern. When not 



used as the power transmission line to the an- 
tenna, the alternate feedline would be shorted 
to reflect a direct continuity of the antenna 
flat-top. To accomplish this, of course, the 
feederline length would be a multiple of ViK. 
With some imagination, the long-wire an- 
tenna can be turned into a versatile radiator. 
The operator who has room enough to erect 
one or, indeed, can only erect such a radiator 
should not discount its possibilities too quick- 
ly, 

...W2EEY/1 



mjlfm 25KC MARKS.' 

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Accurotely! Four wires connect lC-3 Divider to your fOOKC talibrolor to 
give 25KC murk^. Circuit board 1*4" i lU*'. Specify supply voHage 
- 3 300DC, 10 mo, (Lovwcst is besfJ Send for IC-3. S7,2S postpaid. 



PAXITRONIX INC. lOX 1038 <•) Boufder, Colo. M302 




GIANT 



ONLY $24.95 

Postpaid 



NUMBERS-24 HOUR DESK CLOCK 

Can be read from 15 feet in a dense fog. 
Available in Charcoal Grev, Coral Red, Light 
Blue, White or Brown, Ii you don't specify 
we will send one at random. They are all 
beautiful. 12 hour movement also available, 

REDLIWE Co., Box231, Jaffrey, NH-03452 



MAY 1969 



65 



3 



t 



Growing Beams In The Basement 

It is a sad fact that most antenna ''the- 
ory" is rcaily empirical observation . Any 
ham who has tried to concoct his own an- 
tennas can vouch for the fact that no matter 
how good ii design works on paper, the tin- 
snip and hacksaw test is the only one that 
really counts. So why not build them all? 
Before you start buying stock in an alumi- 
num parts factory, consider this idea to niin- 
imi/.e your cost and maximize your gain. 

For years the aviation industry has used 
model phines to guess what might get off the 
ground and not fall apart. Similarly, model 
antennas can be used to find out cheaply 
which designs are likely to give good results 
and which should be slated for the trash. 
First select the highest fre(|uency for which 
you can build a small oscillator. You don't 
need to get too wild, something between 
500 and 1000 mc will give you a halfwavc 
length that will bo vvorkably small. To 
keep peace with the (oca! populace it would 
be a good idea to find one that doesn't 
interfere with TV. 

The transmitter is a simple oscillator of 
whatever type is easiest to build. It is couiv 
led to a simple halfwave folded dipole by a 
piece of 300 ohm TV ribbon. For greater 
effective power a shiiped screen or dish can 
be placed behind it. The receiver is just a 
diode, a ^'apacitot a sensitive microam meter, 
and a varnbic resistor. At K^BDO wc used 
a lab interferometer and obtained several 
promising designs for driven arrays. 

C;enerally. this test system works well for 
determining the radiation patterns, front-to- 
back ratio, and gain of antenna designs. It 
can be used to find both the vertical and 
horizontal patterns, which is hard to do on 
full si/e antennas. It would be a good idea 
to make a dipole and a three element beam 
to serve as standards of measure. One thing 
that cannot be measured accurately is impe- 
dance, due to the effects of random capaci- 
tance and inductance. A lower frequency, 
such as six nielers, must be used to make 
t h es e ni cas u r e m e n t s . 

MatLM'ials for yoiu" donation to the world 
of invention can be almost anything, but I 



TEST 

ANTENNA 
LEADS 



Fig. 1. The test system consists of a simple 
recfirver with a diode, a capacitor, a micro- 
amniecer, and a variable resistor. 




recommend aluminum clothesline and some 
pieces of soft wood. With this equipment 
almost anyone can embark on a career as an 
amateur antenna designer: and if you fail at 
that, you can always try writing articles. 

David B. Cameron, WA4VQR 

Rear Connectors for That 
Imported SWR Bridge 

One of the best all-around values on to- 
day's ham market is the $10 imported SWR 
bridge. But a shortcoming of these units 
is that the connectors are obtrusively placed 
on the ends of the unit rather than on the 
rear. In use the unit is not nearly as compact 
as it looks. Fortunately, it is a simple matter 
to move the connectors to the rear. 

Begin the modification by removing the 
back. Note the pieces of insulating plastic 
and cut vertical shts as indicated in the pho- 
tograph. Unsolder the middle rod at each end 
and lift it straight out. Carefully remove the 
PL-259 connectors. Now cut two pieces of 
scrap aluminum l"xl 54". Drill the appropri- 
ate holes and mount the pieces to take the 
place of the two removed connectors. 





The modified SWR Bridge with connectors 
on the rear. 



Mount the PL-259s on the rear cover, cen- 
tering them 1 1/16" from the end. Place the 
center rod atop the terminals and solder. 
The center rod should now occupy the same 
position as before, but soldered to terminals 
on the rear. Replace the cover, and the mod- 
ification is complete. 

While accuracy on 6 and 2 meters and 
sensitivity in general may suffer slightly with 
the rear connector arrangement, few would 
deny the obvious advantages of the modifi- 
cation. 

James C. Miller, III, WA4IQD 



66 



73 MAGAZINE 



Add This Simple Decimal 
Readout to Your IC Counter 

An integrated circuit counter is a pretty 
satisfying project and I can find no primrose 
paths in Wes Votipka's article in November 
'68 '*73" magazine. One somewhat "un- 
American" (whatever that means) aspect of 
the counter described is that binary read- 
out — you must sum the values of the lights 
on in each decade to translate. There is a 
fine excuse for this approach if illuminated 
readouts are required - in each decade four 
lamps and drivers do the job of ten lamps 
(nine, if zero is understood), drivers and a 
binary to decimal translator. If a diode ma- 
trix is used to translate, forty good, high 
back-resistance diodes are needed for each 
decade! 

Now, my counter is not finished but per- 
haps my readout system will be of interest 
to others still in the building stage. This low 
cost approach gives a true decimal readout- 
I use a separate meter to indicate the output 
of each decade — 50 microampere meters 
function very well when connected directly 
to the outputs of 923 type flip flops. The 
trick is to properly weight the current passed 
to the meter by each flip flop of the decade. 
The circuit Fve used is shown in the figure- 



INPUT 



FLIP FLOP 



FLIPFUQP 



FLIP FLOP 



40K 




FLIPFUOP 



CAWRr 



lOK 



5K 



39K 



Note the binary relationships among the re- 
sistors - the least significant binary digit can 
only introduce one half the current supplied 
by the next more significant digit and so on. 
Logic levels of individual flip flops will be 
different, so equal increments of meter de- 
flection will probably not be observed. 
However, the meter will assume very distinct 
positions for each count stored in the de- 
cade. Purists can trim resistance values to 
equalize deflection increments - Vm satis- 
fied to let the chips fall where they will and 
mark the meter scales accordingly. 

If there are some misgivings about cost - 
50 microampere meters are seldom the 
cheapest on the list - imports go for about 



$3. Bemg pure Scotch I managed to cut that 
by picking up a batch of brand new photo- 
graphic light meters from Olson Electronics 
in Akron, Ohio, at two for a dollar! These 
are 54 microampere movements and, though 
not cased, are beautifully made. I haven't 
tackled the mounting problem but it doesn't 
appear too difficult. Earl Bryant WA7EYR 

San Francisco, Here I Come! 

In connection with the hearing on the Mil- 
ler suit, I will be in San Francisco from May 
26th through the 30th. If any clubs in the 
area are interested in having a guest speaker 
with a lot to say, please drop a note to me at 
73 telling me which night you like. Questions 
answered on anything and everything, if you 

really want to know what's going on, 

Wayne, W2NSD/1 

For Your Next Converter 

Good old Sears & Roebuck has done it 
again. How many times have you battled with 
copper flashing material— trying to get it to 
take solder, attempting to form it into some 
reasonable facsimile of a box or VHF cavity? 
If youVe tired of burned fingers and torch- 
soldering, take heart. Rush down to your 
nearest Sears & Roebuck store and invest 
about $2,50 in a roU of their Zinc-Copper 
alloy flashing* It comes I foot wide, and the 
rolls are 10 feet long. That's a lot of conver- 
ters ! 

It takes solder beautifully. You can lay a 
bead with only a gun --no more torches. It 
forms easily, and cuts with standard scissors, 
or with a paper-cutter. In VHP and UHF ap- 
plications ^ it performs at least as well as cop- 
per flashing -and it silver plates easily, to 
boot- 

Thanks to Jay, K8CJY, for tipping me off 

to this great stuff! 

Bob Grenell, W8RHR 



What's with UFO's ? 



Check in the UFO NET 



on 14,300 kc 



WEDNESDAY NIGHTS at 9 m EST 




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3000 to 8500 Khr. 
±2 Khz, $1,25 
± ,01 % 2,50 

Surface mail 6c, Air Mail 10c extra 

DENVER CRYSTALS 

iRt. 1, Box 357 Parker, Colo rodo 80134 



MAY 1969 



67 




\ 



73 Tests 



The James Research Oscillator/Monitor, Mark 2 and Permaflex Key 




I 

I 



m 



I 



Oscillator/Monitor is a very modest des- 
cription of this extremely versatile piece of 
equipment. Housed in an anodized alumi- 
num case about the size of a pack of cigar- 
ettes, this little unit does just about every- 
thing except stand up and sing **The Star 
Spangled Banner." 

The Mark 2 will serve as a CW monitor, a 
code practice oscillator, an ry detector, an rf 
test device* and a test instrument to check 
diodes and semi-conductor devices of all 
types, 
CW monitoring 

The Mark 2 provides a reliable CW side- 
tone from any amateur transmitter regardless 
of power or frequency. It requires no connec- 
tion to either the transmitter or key. An 8" 
stiff wire antenna picks up stray rf and trig- 
gers the monitor. A strong magnet is attached 
to the back of the case to allow it to be 
placed on the transmitter in the spot where 
the rf pickup will be best. 
Code practice 

The monitor can be connected to any 
keying device to produce a loud, click free 
audio tone, A tone control knob allows for 
adjustment to a comfortable listening tone. 
RF detection and testing 

The high sensitivity and broadband charac- 
teristics of the monitor make it a valuable rf 



test instrument. It will detect the presence 
of rf by producing an audible tone and in- 
dicates relative power of the rf source by 
changing lone. No direct connection is re- 
quired for rf in excess of 10 milliwatts. The 
monitor may be used as an effective tuning 
aid for transmitters or power oscillators. As 
the rf power increases, the tone becomes 
lower in pitch. 

Component continuity and semi-conductor 
testing 

For the testing of circuit or component 
continuity, the monitor has many advantages. 
Tests with the monitor are completely non- 
destructive since the power required can never 
exceed .0025 microwatts and the open cir- 
cuit voltage is not over L5 volts. The maxi- 
mum current that can pass through any com- 
ponent will not exceed 50 microamps. The 
monitor will test component resistances from 
zero to 100,000 ohms. Various resistance 
values will cause the tone of the monitor to 
change. It is possible to test for open or 
shorted conditions as well as partial continui- 
ty. Since the monitor is a polarized device, 
it will test such polarity sensitive components 
as semi-conductors and meters. 

Available by direct mail only at the Mini- 
price of $14,95. 




Permaflex key 

The James Permaflex key is a manually 
operated single pole double throw switch 



6S 



73 MAGAZINE 



THE STELUR - CASE STATION IS NOW A REALIIY 

THE ANSWER TO THE TRAVELING HAMS NEEDS 

An internationally -known DX'er^ Mr* Gus Browning, W4BPD3 is planning to leave on a new 
DX-pedition during the month of February, 1969. He is taking with him two specially designed 
Stellar-Case stations. These stations wiU be contained in two custom cases, containing a Galaxy 
V transceiver for 80-10 meters, power supplies, ren:\ote V*F,0/s, a specially-built Galaxy 160 

meter transceiver, spare parts kits, microphone, keys, log books, tools , meter, and so on. 

Naturally, one case size wiU not meet all requirements, so Stellar has arranged to utilize 
several different sized cases, in order to best meet the customer's requirements. 

A special case will be custom fitted to the customer *s requirements ^ whatever they may be. 
These cases are extra-heavy-duty fibreglass, bound with aluminum. The fibreglass is, in most 
instances, over Vb'' thick, A travehng ham station, which weighs between 35 and 75 pounds, 
is quite heavy^ and requires extra protection. The interior of the SteUar-Case js lined with 
poly-urethane foam to prevent the equipment from moving within the case. 
For a quotation on your Stellar-Case, please submit the following information; 

Make and model of equipment to be installed 

Dimensions of any home brew units 

List of all accessories 

Whether you wish all to be in one case, or in two cases 

Stellar Industries also maintains aa extensive inventory of all major lines of amateur equip- 
ment ^ and consequently can supply these Stellar-Cases complete with aU-new equipment in- 
stalled. Write us for a quick reply quotation. 




i 



stellarlll ndustries 

PIV. OF STEUli r. r>e. 
SALES AND SBHViCB 




10 GRAHAM ROAD WEST 

ITHACA, N Y. 14850 

TELEPHONE: AREA CODE 607 273-9333 



mechanism. It has two independent insulated 
contact paddles mounted to a contacting cen- 
ter support arm. The key is operated by 
Uglit finger pressure against either of the two 
paddles. The key can be used with any elec- 
tronic keyer or may be connected directly 
to a transmitter. The contacts are rated 8 
amps at 28 V dc which is far in excess of most 

transmitter requirements and are the heart of 
the key design since they eliminate the usual 
corrosion and cleaning problem associated 
with traditional silver contacts. 

The sitver contacts have a gold diffused 
coating. 

The key is housed In a poHshed chrome- 
plated steel cabinet 1 9/1 6" square by 3 3/4'* 
long and total weight 'm 10 oz. There axe two 
independent sets of rubber feet. When one 
set is used, the key operates as a side-s wiper 
type of key. When turned to the other set of 
feet, it can be used as a straight hand key. 
Selling for $19.95, it is hard to find a more 
versatile key. 

All James Research products are designed 
and manufactured in the USA and are avaE- 
able by direct mail order only. They carry 
a one-year guarantee* James Research Co., 
Dept. AR-M, 1 1 Schermerhorn Street, Brook- 
lyn, N.Y. 11201. 



the permaf lexkey 

• bolli ■ twin Iftvtr €t tlr^lgKt htnd h«y 
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m 6 am^. gold diffused fllvcr centacii 
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• cabmrt It 16 gaug* polUhed chrom* 
iU«h 1-95" »i|. k3,73\ pdddl*t 
•xt*nd L25*, weight aop. \ pounds 



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cofnpr«ta, 

Bpp. r pounds - ^ ||pd us« 11 con. 

, illicone rubber f«*i lor itabitity. lanrfo dwck Or m*0. 

m \QOi US made 6- guaranteed for I yf. •«»■■* by "»«" «nlr 

James Research company. dep'f: AR- K 
n schermerhorn St., brooklyn n.y. 11201 



COLLINS 

Factory-authorized warranty 
service comes to the east coast 
All Other Makes Serviced 
We service the world— Gov- 
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Amateur Communication 
systems packaging, installa- 
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big, no job too small! 




f:(ILI.lNS 




EISCO 




^iCTIONlQ IHTItNAnOMAL SEKVKf COWOtATION 
1110S BMm STREFT. WHIAT0N» MUUtlTlAND 



MAY 1969 



69 



n 



n 




This antenna requires only half the height of a true 
quarter u;ave vertical. 



'^Compressed'^ Vertical 



F. J. Bauer, Jr,, W6FP0 

P. O. Box 870 

Felton, California 95018 



for 160 



It is not the purpose of this article to go 
into the relative merits of horizontal and ver- 
tical antennas for 160, but rather to present 
an interesting and practical design for those 
amateurs who would like to try a vertical 
without going to excessive heights or resort- 
ing to critical loading gimmicks. As is well 
known, a true quarter wave vertical for this 
band would require a height of at least 120 
feet or so, which is usually out of the ques- 
tion for most amateurs- The antenna des- 
cribed here requires only half this height and 
as far as I can tell by experiment, the radia- 
tion efficiency is about as good as that of the 
full length antenna. 

The basic design of the antenna is shown 
in Fig* 1. About the same conductor length 
is used as would be needed for a fuU length 
vertical. Also most of the horizontal radia- 
tion is cancelled by the adjacent horizontal 
sections of the radiator as shown in the fig- 
ure. Complete cancellation will, of course, 
not be obtained since the antenna currents 
in the adjacent horizontal sections are not 
quite equal and opposite. However^ on-the- 




5&' TO 60 



Fig. 1. Basic antenna wire layout. (Arrows 
indicate instantaneous current flow and can- 

cellatiorr of horizontal radiation. 



air tests at night have consistently shown le^ 
QSB than that obtained from horizontal an- 
tennas, which seems to indicate that the an- 
tenna does behave like a true vertical- 

The antenna is built most simply by sta- 
pling insulated wire to a wooden mast- Do 
not use a metal tower or mast. The antenna 
support I used is shown in Fig. 2, The mast 
is pivoted at the roof level with the lower 
third extending towards the ground as shown. 
Six bricks in a pail are used as a temporary 
counterweight whenever it is necessary to 
raise or lower the antenna. Two guy wires as 
shown were found adequate since no high 
winds are experienced at this QTH. 

The first experimental antenna built used 
no* 12 weatherproof outdoor wire arranged 



TOP SECT. S ^ ^ 



rvH 




GUY 



CENT€« SECT l^^;? 
22* I % 4'S "^ 




Sice 

kU^ BASE 



3'STtFFEHER(2X4) 



FLAT 
ROOF 



REMOVE TO 
PIVOT ANT. 



PIVOT BOLT 



ROOF LI HE 




HANGING 
BOTTOII 
SECTION^ 
20' 2X4 



RE WOVE TO 
PIVOT ANT 

20' 2 X 4 
BOTTOM SECTION 



PIVOT 
BOLT 



2X8 ANT 8ASE 
ATTACHED TO ROOF 



Fig. 2, Antenna support* 



70 



73 MAGAZIIME 




r^.' 



1, 




STRIPPED RG-S/V 



Fig. 3. Antenna configuration using strip 
ped RG 8/U. 



in 6-mch squares as shown in Fig. 1. It was 
about 32 feet high and proved quite effec- 
tive on 75 when worked against ground as a 
quarter wave vertical. The second and final 
antenna was made from old RG8/U coaxial 
cable with the outer braid removed. Since 
the stripped RG-8/U did not lend itself to a 
square configuration, the antenna was made 
in a series of loops as shown in Fig. 3. With 
the dimensions shown, the antenna resonated 
at 21 50 kHz against ground. 

This was a little high for the frequency of 
interest (1990 kHz) and would have required 
making the antenna about four feet longer. 
Since 1 was out of lumber as well as energy, 
I decided to use a simple series tuned anten- 
na coupler as shown in Fig, 4, The coupler 
was also satisfactory for tuning to the I90O 
1925 kHz segment of the band. The simplest 
way to adjust the antenna system is to ''grid 
dip" the tuner to the operating frequency 
and then use the transmitter pi network to 
load the transmitter in the normal manner. 
I had no luck loading the transmitter "pi" 
network directly into the antenna because 
the antenna impedance was too low for the 
''pi" network-about 30 ohms as measured 
on an antennascope. No attempt was made 
to feed the antenna with a transmission line, 
since the antenna base and ground were both 
located right outside the shack window. 
This antenna, like all quarter wave antennas 
requires a good ground system. Radials, of 




»T0 



PI 



XMTfl 
*'NETirOR« 



3 SECTION eC s/ARLABl£ 

All sections \h parallel 

la TURNS ON Z 1/2' FORM 
SPACED Z INCHES 

tZ 9 TURNS CLOSE COUPLED, 
tNTERWOUND, ON LI 



Fig. 4. Antenna Couplar. 

course^ would be best if you have the space 
and the energy to install them. I used three 
eight-foot ground rods in conjunction with 
three water pipe ground connections, all tied 
together. The antenna current was the same 
whether a half wave or quarter wave antenna 
was used, so I assumed that the ground sys- 
tem was fairly efficients 

As for results obtained with this antenna, 
I have had neither the desire nor the ambi- 
tion to operate odd hours and check the an- 
tenna on some real DX- However, tests run 
with stations 250 miles or so out indicate a 
two S-unit gain at times over a low horizon- 
tal antenna. Strangely enough, stations clo- 
ser in (40 miles or less) favor the horizontal 



60* 




32'(Af*PR0X 



Fig, 5. Inverted "L" configuration. 

antenna by two S-units or so. Excellent re- 
ports have also been received when working 
Idaho and Wyoming stations from this QTH 
with 50 watts input. 

For those amateurs who think 60 feet or 
so is still too high for an antenna, 1 suggest 
an inverted *'L" configuration as shown in 
Fig* S. The antenna is, in effect, a 1/8 wave 
vertical with a 1/8 wave horizontal wire add- 
ed- It has given a good account of itself as an 
all around 160 meter antenna both for DX 
and local work and is only 32 feet high. 

No matter which antenna type you decide 
to build, you will be sure to have a conversa- 
tion piece— on the roof, that is- 

.„W6FPO 




MAY 1969 



71 



4 




Seven- Step Class 

Transistor Amplifier Design 



Edward A. Lawrence, WA5SWD/6 

218 Haloid 

Ridgecrest, California 9355S 



Designing a Class A transistor amplifier is 
not so hard if you are willing to make a few 
reasonable assumptions. As a matter of fact, 
it h just an exercise in Ohm's Law. The 
biggest assumption is that the transistor has 
reasonably high gain, and a reasonably low 
leakage- This procedure works for NPN, 
PNP^ Silicon and Germanium, You don't 
care if it is Ge or Si until the 4th step, and if 
it is NPN or PNP until the last, 

rf you need a particular gain (voltage 
gain)^ you can determine the proper values 
to get it, or if you want all the gain you can 
get, take the same procedure, but bypass the 
emitter resistor. Refer to Fig, 1 for the seven 
steps and an example to show how they are 



Once you have designed the amplifier and 
assembled it, check Vc. It should be about 
one-half the supply voltage. If it isn't, 
change RB2. Increase it if Vc is too low, or 
vice versa. If you build for a set gain, 
remember to allow for the loading of the 
next stage by figuring the load in parallel 
with RL in step 2. If you decided to go all 
out for gain, pick CE to have a reactance of 
about one-tenth the value of RE at the 
lowest frequency you plan to pass through 
the amplifier. 

This procedure will allow you to design a 
workable amplifier for almost all applica- 
tions for Class A RC coupled amplifiers. You 
may come upon a special case, but 1 have 
developed this procedure while working in 
various Engineering Departments during the 
last three years^ so 1 sincerely doubt it- 

Additional Remarks 

Step 1: To be able to gel the maximum 
voltage swing out before clipping, the col- 
lector needs to be set one-half the effective 
supply voltage below supply voltage. To find 



ifii 



'Wur o- 



^^■ 



*tB. 




■O ys 



^f — OauTP^ii 



^vi 



Fjg. \ 



1. Pick RL (.6-20K) IC=.5VS/RL 

2. Calculate RE (Gain 1 25) RE = BL/Gain 

3. Calcufate VE {IE about equal to IC) 
VE=IC(RE) 

4. Add VBE to VE to get VB. VBE=.3v for Ge, .6 
for S* VB-VE 4 VBE 

5. Pick RBI t3.3-27K) 

6. Calculate RB2 
RB2=RBHVS-VB/VB) 

7. If NPN, VS is Positive 
If PIMP, VS is Negative 

Example: NPN Si, 12VDC, Gain of 10 

1. RL=10K JC=6/10K=.6 ma 

2. RE=10K/T0-1K 

3. VE = .6x10-^x1x103=.6VDC 

4. VB^. 6+6^ 1,2V DC 

5. RB1 = 12K 

6. RB2 in K ohms 

RB2-12(12-1.2/1.2) = 12(9)^108, use 110 K 

7. VS Is Positive 

effective supply voltage, subtract VE from 
VS. Then drop half of that across RL. 

Step 2: This step presumes that the gain 
of the transistor is higher than the gain the 
circuit asks for. Normally this will be the 
case. If you want all the gain you can get, 
bypass the emitter resistor. This will increase 
the distortion somewhat. Usually the distor- 
tion wiJI still be low enough for amateur 
purposes, but not low enough for ''Hi-Fi". 

Step 3: Since the base current is small 
compared to the collector current, this is a 
good approximation. It is not advisable to 
ground the emitter directly, as this reduces 
the dc stability greatly. It also makes this 
procedure almost useless, since some of the 
assumptions no longer hold. And one re- 
sistor and a capacitor are a very small price 
to pay for the advantages gained. Also, as a 
rule, the more voltage you drop across the 
emitter resistor, the more stable the circuit 
will be with temperature changes. 



72 



73 MAGAZINE 



FOR BETTER COMMUNICATION 

INSIST ON A GAM ANTENNA 
MARINE -BASE- MOBILE 



Step 4; In actual practice, VBE will not 
be exactly .2 or ,6 vdc, but these values will 
be very close. The emitter follows the base 
voltage, and not the reverse, as this proce- 
dure might seem to indicate. But this is the 
simpler way to design the amplifier. 

Step 5 : No correction has been made for 
base current, so VB may be slightly lower 
than this step indicates. The lower RB 1 and 
RB 2 are, the less base current will affect the 
result. But this also lowers the input imped- 
ance, which makes the amplifier harder to 
drive* 

. . . WA5SWD/6 



Even Better Gamma 

In the Sept. '66 73, the improved gamma 
match can be further improved by using the 
printed circuit board in one piece as in Fig. \. 
This makes for a neater job and less chance 
of wire breakage. K6ZH0's idea is a fine one. 



SOLDER SRAID 
THRU HOLE TO 
OTHER SIDE 



COPPER DM 
BACK SJDE ONLY 




c:;; 



NO COPPES OP* 
EITHER SIDE 

SOLDER TO BACK SlO€ 



20 METER SHOWN 



U IJ/Z' — M 

Ffg. 1» Details of the improved gamma-match. 

The boards should be of either epoxy or 
polyester. These will absorb less moisture 
and stand up better in the weather. Newark 
lists both of these items in their catalog- The 
epoxy 3x6 is $L14, # 19F3213, The poly- 
ester 3x6 is $ ,73, # 19F3228. Kepro is the 

vender* 

Paul A. White, W6BKX 



MORE RANGE 




ELIMINATE IGNITION NOISE 

ELECTRO -SHIELD® 

YOUR EN GINE 

FROM ^^^~^ 



ESTES ENGINEERING CO. 

543 W. 184th St., Gardena, Calif. 90247 



4-Element Quad 



$111 



95 



GUARANTEED/ 

SKYUNE PRODUaS 

406 BON AIR AVE. • TEMPLE TERRACE, FlA. 33&17 



4 NEW TUNAVERTER LINES & SQUELCH 



.j^fUP^Vttl» 



Tunable and crystal controlled RF 
converters for monitoring Police, Fire, 
Amateur, CB, ZK^, VHP weather, etc., 
on your broadcast radio economical- 

See listing of models int^r. issue of 
73, page 21. 

HERBERT SALCH & CO. woodsboro 7, rx 73393 




MAY 1969 



73 



A Cheap and Dirly 15-Meter Antenna for the 



Lon^haul DX 



Paul Cook III WA7CSK 
2943 N.E, 178th Street 
Seattie, Washington 98155 



The $4,98 Novice Special 



There's no doubt about it, with the 
sunspot cycle where it is now, 15 meters is 
the best band for the Novice who wants to 
work the world. Openings to aU continents 
occur daily, and flea powered Novice sta- 
tions are picking off the rare DX like 
shooting fish in a barrel- The word seems to 
be getting out, and now more and more WN 
callsigns arc heard on 15. When tiie choice 
DX moves in on frequency, there are even a 
few pileups — an occurence formerly re- 
served for 20 meters. If you want to work 
ALL of the DX with good consistency, 
you're going to have to have a good signal. 

Most Novices today run 75 watts into a 
simple dipole antenna^ but if you want to be 
"top dog'' in the pileups, you'll just have to 
do one better than the next guy. One way of 
doing this is to increase your transmitter 
power beyond the Novice limit of 75 watts- 
However, that just means big trouble with 
the FCC, so a better thing to do is to put in 
a better antenna. In this article I*m going to 
show you how to build a beam antenna that 
wUl beef up your signal so that you can 
really '*sock-it-to-'em" on 15. 

The antenna that I am going to describe is 
called a phased vertical array. It consists 
basically to two 1/4 wave vertical antennas 
with 1/4 wave radials placed 3/8 wavelength 
apart- The antenna is fed with appropriate 
matching and phasing sections and has a gain 
of about 6 db. This 6 db of signal improve- 
ment is the same as if you changed your 
transmitter power from 75 watts to 300 
watts! The antenna is very cheap and easy to 
build, and you might have all of the parts, so 
then it may cost you nothing. 

Theory 

Basically, the antenna consists of two 
vertical ground plane antennas placed in 
"phase" with each other. This means that 
the two ground planes are placed at a certain 



Parts List: 

200 ft. of wire 

2—2x4 boards, about 12 ft. long 

25 ft- of RG59/U coaxial cable 

50 ft. of RG58/U coaxial cable 

E lectncaf tape 

Solder 

4— egg type insulators 

distance apart so that the signals from both 
antennas complement each other and pro- 
duce higher radiation in one direction. This 
works the same for receiving. In this way we 
(1) reduce QRM to stations in other direc- 
tions because they don't hear us, (2) reduce 
QRM from stations in other directions 
because we don't hear them, (3) increase our 
signal strength in the desired direction, and 
(4) increase the received signal strength from 
stations in the desired direction. This ail 
adds up to higher station flexibility and 
efficiency. 

Construction 

To build the antenna you will need the 
materials that are listed in the parts list. The 
two boards can be mounted on the side of a 
roof, like my own installation, or mounted 
on the ground. Before you erect the boards, 
pound a nail in each end of both. Then 
measure out 1 1 feet of wire and connect it 
to two egg insulators. Do this for both 
boards, and be sure to solder. Next, take 
fishiine, rope^ Or what have you, and string 
up the wires vertically on the boards, tying 
the insulators to the nails. Then erect the 
boards. When you do this, be sure that both 
boards are vertical and 16-1 /2 feet apart. 

Feedline and Matching Section 

Now you have constructed the antenna, 
and it's time to piece together the matching 
section and feedline. 

Take one 1 1 foot piece of RG59/U 75 
ohm coax and splice it to an 11 foot piece of 
RG58/U 52 ohm coax, as shown in Fig. la* 
Do a neat^ careful job and wrap the connec- 
tion well with electrical tape. If you have 
some Krylon spray, use it on the connection 
to do a completely weatherproof job. 

Get 11 feet of RG59/U and the RG58/U 



74 



73 MAGAZINE 



Fig. 1A 



fl<j 




RG 



firSPLlCE CENTER COfJOLTTOH. THE'S SOLDEfl 



AG 



^v^;^r ...,j]mn^ 



ft^ 



(21 'HHAP CGNNECTIQM WITH ELECTRICAL TAPE UNTIL iT REACHlS 
LEVEL Of SHIELDING 



RG 




RG 



E3)Wf*AP TWO LAYERS OF BARE HOOKUP WIRE OVER THE ENTIRE 

CDNNECTION. THEN SOLDER 



RG 



IIIUini/IIIITT] 



RG 



C4J WRAP ENTIRE CONNECTION WiTM TAPE 



Fig. IB 



jw ijuur 



iU SAML AS N0U»AeOV£ 




h 



^iiiiiiy;; 



{2 J SAME AS NO (£J ABOVE 



Pr 



jLjl 



h 



f3)SAHE AS NO (S» ABOVE 




^ 



iDiiDi i ^/Jinin 



t4) SAME AS NO {41 ABOVE 



that goes to the shack (as shown in Fig, 2) 

and make the three way splice as shown in 

Fig. lb. Here again, if you have Krylon, use 

it. 

Now lay out the matching section on the 

ground or the roof. Don't coil up the coax 
or let any kinks get in it. Instead, lay it out 
so that it lies in a gentle curve with no sharp 
turns as shown in Fig, 2, Solder the center 
conductors from the two ends of the match- 
ing section to the antenna wires at the base 
of the boards as shown in Fig. 3, Then solder 
the outer conductor and eight or more 1 1 
foot ground radials to the nail on each base. 
Run each radial out from the base fairly 
perpendicular to the vertical boards and lay 



n 



SIGNAL DIRECTION 






^''^^ 



l^-'^yu*-,. 



.^^ 



'^ 



-■^ 



-'-''"r^^--. 



RG59/U 
COAX 




ffG So/ii 



RG59/y 
COAX 



zzz 



JZZ^ 



SPLICE 




Frg. 2 



SPLfCE 



RG 58 /« 
TO SHACK 



them on the roof or ground in a fashion 
similar to the spokes of a wheel. The radials 
improve the low angle of radiation which 
brings in the long distance signals better 

Operation 

Now that you have completed the an- 
tenna, try it out on the air! When I tried 
mine out with the antenna aimed toward 
Europe the first time on the air^ I knocked 
off two SM*Sj a G3, and II, and a DL with 
only 75 watts. This little antenna is a real 
bomb! If you wish to change the directivity 
of the antenna, then substitute PL-259 




Fig. 3 



ANTENNA W»RE 



2t4 MAST 



FISHLrWE 
OR STRfNG 




SOLDER THE SHIELD 4N0 
THE RADIALS '^O TIGHT 
NAIL, 



RAOIALS 




\ 



\ 



1 



MAY 1969 



75 



i 





CASSETTE TAPE RECORDER 

After testing a dozen different 
nnakes of cassette tape recorders 
we found that the Valiant was by 
far the easiest to use. The fidelity 
is good and the push button sys- 
tem outstanding. Has battery lev- 
el meter, recording level meter, 
jack for feeding hi-fi or rig, oper- 
ates from switch on mike. Great 
for recording DX contacts, friends, at the movies, 
parties, unusual accents, etc. Use like a camera. 
Comes with mike, stand, batteries, tape. 

SPECIAL, ONLY $33.00 Postpaid 

24 HOUR CALENDA R CLOCK 

This beautiful clock reads 
the day, the date and the 
time in large, easy to read 
numbers. Set this on GMT 
and never make a mistake 
again on logging time or date. 8x3T^x3%, brushed 
aluminum case. Synchronous self-starting move- 
ment, 1 15v 60 cy. Make your operating desk look 
outstanding with this new type of clock. 

24 HOUR CLOCK, $4L00 Postpaid 
12 HOUR CLOCK, $4L00 Postmid 

TRAVEL-CLOCK RADIO 

Eight transistor clock radio, 
complete with clock, radio al* 
arm and slumber setting! Wei- 
ghs less than VA lbs. Great 
gift for traveling friend or rel- 
ative. Batteries included* Tray 
opens to hold change, etc. 

SPECIAL, ONLY $24.00 Postpaid 

AM-FM DIGITAL CLOCK RADIO 

Here is something new— a 
digital clock [reads num- 
bers directly) plus sensitive 
AM-FM radio with AFC! 
Compare with $60 Sony. 
This is a wonderful radio for the bedroom or kit- 
chen. Transistorized radio. Antenna built in for 
local stations. Use outside antenna for distance. 

SPECIAL, ONLY $38,00 Postpaid 

DESK NAME-CALL PLATE 

Your name and call on a w?!- 
nut grained desk plate 10" 
long by about 1" high. Up to 
20 letters and spaces. You 
can have your full name or 
your first name and call let- 
ters. Sorry, no zero available. 
Identify your station with a beautiful desk plate. 

SPECIAL, ONLY $2,00 Postpaid 

REDLINE Co. Box 431, Jaffrey NH 03452 

( J Tape recorder ( ) Digital clock radio 

j ) 24 Hour clock ( ) 12 Hour digital clock 






1 
I 

I 
I 

I 

I Name 

' Address 



Travel clock radio 



Desk name plate 



coaxial plugs^ a double female connector, 
and a Tee connector for the splices. If you 
connect these as shown in Fig, 2, you will 
have your signal aimed in the direction 
shown. But if you take the RG58/U match- 
ing section out, and connect it exactly the 
same way, only on the other side of the Tee 
connector, you will reverse the direction of 
your signal If you leave out the RG58/U 
matching section altogether, you will end up 
with a figure eight type bidirectional pattern 
that is perpendicular to the two previous 
patterns. 

In conclusion, if you try this antenna, Vm 
sure that you*ll work a lot of DX, The 
.antenna is efficient and works well, and will 
help you to get the edge on the other 
stations- If anyone has any problems with 
this antenna, please write to me and Til be 
happy to advise. If you build this antenna, 
write to me anyway and tell me how it 
works! 

. . , WA7CSK 



I City_ 
I State. 



Zip 



FCC ACTS TO REVOKE AMATEUR 
LICENSES OIM OBSCENITY CHARGES 

The Federal Communications Communi- 
cations Commission took action today to re- 
voke the operator Ucenses of three Amateur 
Radio Service operators on charges of ob- 
scene, indecent or profane radio communica- 
tions. The Commission ordered Steven P. 
Bowman, of Sikeston, Mo,; Kenneth C. Henry 
of Anderson* Inc., and Gary Overman, of New 
Castle, Ind., to show cause why their Ucenses 
should not be revoked. The three operator 
licenses were also ordered to be suspended. 

In addition to the obscenity charges, other 
violations included transmission of false or 
deceptive signals or communications, failure 
to identify stations properly, transmission of 
unidentified communications or signals and 
willful or malicious interference to radio com- 
munications of other amateur stations. 

The Commission said that the three ama- 
teur licensees had repeatedly and willfully 
violated the Rules. The enforcement actions 
followed investigations carried out by the 
FCC Field Engineering Bureau and the FBI 
after complaints were received from other 
amateur radio operators. 

Actions by the Commission March 14, 
1969, by its Chief, Safety and Special Radio 
Services Bureau. By Orders, and Orders to 
Show Cause. 



76 



73 MAGAZINE 



How to Fly Your Kite 



M. B, Crowley, EI4R 
75 Church Street 
Listovrel, Co~, Kerry 
Ireland 



(Or a vertical long wire on last Year's EI0RF Expedition) 



The location of the expedition "BEAR" 
island (rechristened "BEER** island) was 
good, but the shack QTH was surrounded on 
three sides by mountains- The problem was 
to put out sufficient wire for our L7 MHz 
bands; and 260 feet of wire can present quite 
a problem on such a location. A vertical 
aerial would be fine, but 260 feet of support 
pole was out of the question on an island ex- 
pedition. Gas- filled balloons are not easily 
come by where we were located- The solu- 
tion-yes—a kite. 

Having in mind from my boyhood days 
the dimensions of a small kite without frills 
or tails that^ once aloft, in a light breeze 
could be tied to a convenient peg and forgot- 
ten about, it seemed to me that this was the 
ideal solution- 
One of our boys gave me some 260 feet of 
braided copper wire from the old emergency 
TX "The Gibson Girl" used by aviators in 
the Second World War. This wire seemed 
ideal to fly the kite with and weighed only 
one pound- 
Having some half-inch (average) diameter 
bamboo, garden variety poles on hand^ and 
having persuaded the XYL to let me have 
some old bed sheets from her junk box, the 
next undertaking was to scale up the original 
version of the kiddie kite. 

From the diagrams it can be seen that the 
dimensions and shape are straight forward 
and present no mathematical problems to 
scale up to the required size. In my case, this 
amounted to bamboo poles of 5 feet in length- 
The materials required are four bamboo 
poles, one large section of sheeting and two 
smaller sections of sheeting. Three lengths 
of tough light cording are also required- The 
illustrations give the dimensions of these 
pieces. When cutting the cloth, do not for- 
get to include that extra width of cloth on 
the leading edges of the wings, which^ when 
folded back on itself and stitched, will hold 
the two pieces of cord that strengthen the 
wing edges- 

It would at this stage be advisable to sec- 
ure the services of the XYL or YL to machine 
stitch the edging. Go careful here, for this 
sort of favor could cost you later; why else 



i^Cllt liiil' I. 







Tt* Om mi MP cot* 
n.1 lid 



tftK^SpH tfiitlH.** KtAlilw: 



do I write this article for 73 Magazine? 

The center pieces are stitched with a larger 
overlap to hold the bamboo poles, which 
should slip into place with a reasonably tight 
fit, the ends being then stitched over by hand 
needle to hold the poles permanently in place- 

The overall weight of the kite and poles 
was 3 pounds. The down wire should be tied 
approximately a quarter way down the tie 
cord. Unwind about 50 feet of the down wire 
and have a helper push the kite up into the 
wind with the downwire held tight. In a 
modest steady breeze the kite wiU lift gently 
and the remainder of the wire can be paid 
out. If the kite pulls too hard and slips 
sideways, tie the downlead further up the tie 
cord until balance is achieved and the down- 
wire is near verticaL In a light breeze and 
from the puU on the downwire, it seems to 
me that this size kite could support about 3 
pounds of downwire- 

One word of warning. If the breeze is 
strong, do not allow the junior operator to 
play around with this size kite. There are 
easier ways of flying nowadays. Once the kite 
is aloft, with the required length of wire, tie 
the downlead to a convenient tie point, 
through an insulator- A lead to the shack 
from the tie point will give you a vertical 
antenna without match, provided the wind 
remains. Force 9 winds should be avoided 
as your favorite rig may disappear out the 
shack window, Happy flying hours, fan- 
winds and tight wires* 

-.EI4R 



MAY 1969 



77 



m^ 



I 



In Search 



Teas ha pas, K9Y0E 
14925 Evers A venue 
Dolton, Illinois 60419 




a 



Better 



Angle 



Observations and Suggestions Involving HF Radia- 
tion A ngle Manipulation 



When HF DX-getting tactics are dis- 
cussed, sooner or later the subject wHl center 
around antennas, for the antenna, coupled 
with its geographic positioning, will ulti- 
mately make or break a DXer, A status is 
eventually achieved, however, when the 
serious DXer has put up the largest and 
taEest antenna he cared or dared to, or a 
point of "signal strength stagnation" is 
reached. For most of us this is a frustrating 
level, for it probably still means an S-unit or 
three gap between us and the big guns. Even 
if you feel you're near the top^ however, 
there were undoubtedly times when these 
extra db would have come in handy. This 
article is no magic panacea for combatting a 
W3CRA or W5VA in the pileups, but 
knowing a little about radiation angle manip- 
ulation may give you something to think 
about along those lines. 

Low angle advantages 

I think many of us have operated enough 
to realize the importance placed upon an 
antenna with a very long boom perched 
upon a very high tower. The fellows with the 
biggest combinations of these two, possibly 
coupled with an elegant location, constitute 
the big guns, or the big DXers and contest 
winners, 

A major reason for their seeming invul- 
nerability is the very low vertical radiation 
angles associated with such an antenna com- 
bination. For normal F2 propagation paths, 
the best situation is for your signal to reach 
a distant point in the least number of 
''hops" or reflections. Up to about 2500 
miles Of so. one hop propagation is possible, 
but after that, an earth reflection is neces- 



sary. Now the signal is being decreased by a 
number of losses; most pertinent here are 
distance losses due to spacial spreading, and 
ground losses at each earthly hop. Distance 
loss is of course a function of distance; a 
lower reflection angle means less distance 
travelled and therefore less loss than a higher 
angle, although the difference may only 
amount to a db or two. Much more impor- 
tant are the ground losses. While sea reflec- 
tions are less critical of incident angle, 
ground reflections may result in four or five 
db differences per hop between low and high 
angles, depending upon frequency (1). Here 
is one place where the big guns clean up! 
One or two less of these lossy earth hops 
experienced by signals approaching from a 
high angle and we're talking about S-units of 
difference. Fortunately, all is not this rosy 
for the people with the low take-off angles. 

NBS observations — good news? 

The good news is that in most cases, these 
things I just talked about occur only for 
"storybook" propagation under ideal condi- 
tions, Wliat about the real world? W. F. 
Utlaut presented an interesting report along 
those lines in our National Bureau of Stand- 
ards research journal Radio Propagation 
where he made a detailed study of radiation 
angle importance. The results were slightly 
astounding (2), 

Using a VOA transmitter in Munich, 
Germany, and receiving antennas in Boulder, 
Colorado (a receiver was also located in 
Slough, England, but results were consistent 
with those in Boulder), all with carefully 
calculated radiation patterns, Utlaut at- 
tempted to find out if low angles were that 



78 



73 MAGAZINE 



Height 


Radiation Angle 


ft 


deg 


50 


15.6 


135 


5.2 


310 


2.3 


485 


1.4 


985 


0.7 



Boulder Antenna 

1B 
28 
3B 

4B 
58 



Table I ^ 

good. From March to June, 1959, on 20 
MHz, the Munich station transmitted while 
the receivers in Boulder carefully recorded 
daily signal variations. Five receiving an- 
tennas were used, varying in vertical radia* 
tion angle from -7 to 15.6 degrees. Table 1 
lists the various antennas, heights, and asso- 
ciated radiation angles, while Fi^, lA^ IB, 
1C» and ID are graphs of hourly median 
signal strength for the Munich to Boulder 
path from March to June. Transmitting 
antennas at the Munich end were rhombics 
and vertical main lobes between 12 and 16 
degrees (two antennas used). 

While receiving data extended through 
times when the predicted MUF (Maximum 
Usable Frequencies) were below the oper- 
ating frequencies, this may be sUghtly im- 
practical from the amateur standpoint where 
relatively low power is usually employed. 
Close inspection of Figs. 1 A-D will bring out 
a number ol interesting points: 

1, No one radiation angle dominated for 
an entire average day during the time 
the band was open. (MUF greater than 
20 MHz J 

2. Low angles seemed more of an asset 
during a summer month (June) than 
during a spring month (March). In 
addition, the spread of signal strength 
between one angle and another was 
greater during the summer months 
than during the spring. 

3, Lower angles were characteristically 
*'band openers" with dominance here 
noted in excess of three S-units over 
the highest angle. 

4. Higher angles seemed valuable during 
the midday hours, with some advan- 
tages over the lowest angle in excess of 
two S-units at these times. (Remember, 
these were monthly averages; there 
were undoubtedly times when these 
differences were greater.) 

The basic observation by Utlaut in this 
report was that statistically, and over an 
average 24-hour period, best results could be 
gained by using the lowest radiation angle 
possible. This involved limes when the pre- 
dicted MUF was much below 20 MHz; which 

(WAY 1969 



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00 a a CE 04 js €1 07 » di u a is h is h if « 9 io ;i Z2 23 |4 

Ffg. 1A. Hourly median signal strength for 
Munich to Boutder path, March, 1959. 









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00 <1 Q? CQ (M OS 0£ 07 CM 09 O II I? U 14 15 ^ M m n ^ l\ 12 II 24 

Fig. 1B. Houfty median signal strength for 
Munich to Boulder path, April 1959. 



^"^^:^:'//r-t 



lis 
4%^ 







00 W K 01 04 « 06 or 06 09 C u ij t| :i IS J* \t <6 (9 M I 17 tV 14 

Fig, 1C. Hourly median signal strength for 
Munich to Boulder path. May 1959, 



-as 

■IS 



' — \' 



ntcoiCTCD Mur^'io hc/s 




1X9 01 ce 03 CH 03 06 0^ 01 Oft M I? u M 13 f( rr tfl f? 20 ^1 2j n ^4 



Fig. ID, Hourly median signal strength for 
Munich to Boulder path, June, 1959. Trans- 
mitter in alt cases was off the air from 0500 
to 0800 MST, (1) 



79 



J 



would probably mean communication below 
amateur capabilities. Looking at times when 

the MUF was 20 MHz or above, or when the 
band was open for possible amateur con- 
tacts, seems a slightly different story, with 
the "best" angle rapidly changing with time. 
The two most practical antennas, with real- 
istically achievable angles, were IB and 2B, 
representing the small time DXer (height 50 
feet, angle 15.6 degrees) and the big gun 
(height 135 feet, angle 5,2 degrees) respec- 
tively. Although most differences between 
these two antennas were in the range of 5 
db, special note shoul(l be taken of the April 
graph at about 1600 MST when antenna IB 
(small time DXer) had the astronomical edge 
of 40 db over antenna 2B (the big gun)! 

Possible explanations — ray paths and angles 
Reasons for such phenomona are varied 
but usually of a complicated nature; the 
important point is that they do exist. A 
possible '*easy'' answer seems to lie in 
another recent finding by our Bureau of 
Standards; while a low radiation angle nets 
great skip distances, in most cases the 
absolute longest skip is achieved by a very 
high angled ray. Fig. 2 illustrates. Ray paths 
1, 2, and 3 follow the generally accepted 
propagation theories - the lower the take- 
off angle, the greater the distance. Ray 5, 
however, the highest angled ray before iono- 
spheric penetration takes place, actually 
out-distances the lowest angled ray! This is 
apparently the case for most propagation 
paths, as shown in another NBS graph. Fig. 
3, This shows in a general case, that for any 
skip distance D, two ray paths are possible at 
any frequency below the exact MUF — 
either a high or low angled ray. Note, 
however, that the high angled ray is critically 
dependent upon the correct angle. Note also, 
in Fig, 2 again, that the high angle signal is 
spending much more time in the lossy 
ionosphere than the lower angles. 

Fig, 4 depicts even a more frightening 
possibility. This is a government ionogram, 
or graphical picture showing path time ver- 



MAXtMUM 

ELECTRON 

DENSiTY 




IONOSPHERE 



SKIP zo^r 



Fig. 2. Possible ray paths at a fixed frequen- 
cy with varyfng vertical radiation angle. Note 
that the highest angled ray, #5, outdistances 
even the lowest angled ray, #3, (2) 



HIGH 




LOW 



$ 



Fig. 3. Variation in skip distance D with 
vertical radiation angte . Note how criti- 
caHy dependent the skip distance is upon 
small changes in angle for the high ray, (2) 




47 lAc/i 




HI&H HAY 



fi 









Fig. 4* Ottawa, Sfough ionograni for Novem- 
ber 14, 1957 at 1556 UT. Note that above 
39 MHz only reflection of the high angle 
ray occurs, (2) (By permission of the 
Chief Superintendent DRTE.) 

sus frequency, for, in this case, an Ottawa to 
Siough, England path. The horizontal lines 
show the high and low rays as reflected by a 
pulsed signal The "omigosh"' data here is 
that above 39 MHz, reflection occurred only 
with the high angle ray; low angle reflection 
was simply nonexistant! 

A tew more easily talked about reasons 
for the '"best" angle to vary involve the great 
number of possible paths that a ray may 
*'use" when skip distances are great- Fig. 5 
illustrates two cases that could prevail along 
a DX path, although any combination of 
these hops are possible. Sporadic E clouds 
enjoy floating around, particularly during 
the summer months^ and may enhance or 
belittle a band opening if one is hit. Since 
they are relatively small, a difference in 
take-off angle may result in a miss by one 
station, a hit by another, constituting dif- 
ferent paths travelled, and ultimately dif- 
fering signal strengths at the DX end. A 
similar situation may exist for the more 
stable E and Fl layers as weU. Also, as 
suggested in Fig. 3, the number of possible 
paths decreases as the operating frequency 
approaches the MUF, The NBS tests were 
started in the spring, with the daytime MUF 
much above the operating frequency at that 
phase of the sunspot cycle, so many com- 
binations of paths were possible. Many were 
apparently high angled paths. As summer 
approached, the daytime MUF was nearer 20 



80 



73 MAGAZINE 



MHz, and consequently less paths available; 
the last ^ path to go (at the exact MUF) 
apparently is characteristically low angled, 
hence the better results with low angles in 
the summer. Finally, the ionosphere is full 
of simple Haws, such as "thin'' and ''thick'' 
spots, holes, and tilts, all of which play 
important roles in determining which path a 
signal may take, and all of which in some 
way are connected with the incident signal's 
vertical takeoff angle. What Fm trying to say 
is that there apparently is no year-round 
"best" angle, and for consistent results, it 
would be nice to be able to change the 
antenna's radiation angle quickly and accu- 
rately. 



to* 




Fig. 5. Possible ray paths for typicaf F 
propagation. Any combfnation of these 
and E-layer bounces nnay occur. 



Three methods and results 

Accomplishing this accurate radiation 
angle change is not as hard or expensive as 
might be guessed; many DXers have un- 
doubtedly tried the suggestions Tm about to 
present and have, hopefully, met with some 
degree of success. Ill concern myself with 
horizontally polarized antennas only, since 
they are not as greatly subject to ground 
losses that vary from place to place, and 
since they are more highly regarded in DX 
circles. 

The vertical radiation pattern of anyone's 
antenna is, of course, a point by point 
multiplication of antenna's free space 
pattern and the ground reflection pattern. 
The free space pattern is dependent upon 
the antenna's ability to focus the signal; the 
lobes or plots of transmitted intensity from 
such an antenna will lie at an angle of zero 
degrees with the horizontal. Ground reflec- 
tion patterns of any horizontal antenna are 
basically a function of antenna height above 
a perfect ground. These two patterns, plus a 
small compensation factor for those of us 
without a perfect ground, as well as con- 
siderations for trees, buildings, wires, or 
other obstructions, make up the real radia- 
tion pattem. Fig. 6 shows a simple example 
of this three step process. 

The Armstrong method 

Antennas with parasitic elements are little 



I80* 




£70* 




Fig. 6. Example of real radiation pattern 
determination. Fig, 6A is the vertical pat- 
tern of a half -wave dipole in free space for a 
ptane perpendicular to the wire axis. Fig. 6B 
is the vertical ground reflection pattern in all 
directions for such an antenna at a height A 
above a perfect ground. At the same time, 
6B is the ideal resultant when A and the 
ground reflection pattern are multiplied to* 
gether point by point for a plane perpendicu- 
lar to the wire. The dotted line represents a 
possible final result taking into account ob- 
structions and a less than perfect ground, (3) 



BEAM 




ft* 



rrrrrrrrrrrrfV- 



Fig, 7. Overlayed patterns of a reference 
dipole and a three element parasitic array, 
both at a height of one wavelength. Verti- 
cal lobes of both remain at same angle of 
elevation and depend only upon height above 
ground, (4) 

different in these respects, as shown in Fig. 
7, Probably the simplest method of radiation 
manipulation, then, would involve changing 
the multiplicative ground reflection pattern. 
Since for horizontally polarized antennas, 
the ground reflection pattern is a function 
only of height above ground, this is easily 
accomplished by varying the antenna's 
height. Fig, 8 shows graphically this relation- 
ship for antennas over flat terrain. Note how 



MAY 1969 



81 



J 



mm 



2 5 








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♦0 (5 20 

RAOtATfON ANGLE Qf MAIM lOBE 



25 



30 



Fig. 8. Relationship between main radiation 
lobe etevation and hetght above ground for 
horizontal antennas above flat terrain. Note 
how difficult takeoff angles of less than 5 
degrees are to achieve in such a situation, 

difficult it is to achieve take-off angles of 
less than 5 - Fortunately, the severe require- 
ments of this graph can be lessened if the 
antenna foreground is sloping. The math 
becomes a httle embarrassing, but your 
actual radiation angle can be calculated in 
such a situation. A more complete analysis is 
given in "Radio Transmission in the Lower 
Atmosphere" by Bailey, Bateman, and 
Kkhy, PIRE, October, 1955, 

Lowering or raising the antenna is then a 
distinct possibility and although frequently 
practiced, it's usually agonizingly slow, and 
hard on arms and winches. It can be helpful, 
however, for short operating periods, such as 
contests or DXpedition chasing, when the 
towering or raising need only be done once 
or twice per day, 
Stacking 

A much better method involves vertical 
stacking. While not going into the rigors of 
stacking dimensions, (A very good analysis 
can be found in "Optimum Stacking 
Spacings in Antenna Arrays" by H. W. Kas- 
per, K2GAL, QST, April, 1958,) 1 wiU say 
that for best results, the antennas should be 
stacked for maximum gain, with the bottom 
bay at least X/2 off the ground, more if 
there are numerous obstructions. For three 
element yagis, this involves spacing, of at 
least 3/4 A, a troublesome distance for 14 
MHz, but a distinct possibility on 21 and 28 
MHz, Aside from the three db maximum 
attainable gain if done correctly, this stack- 
ing sharpens the vertical lobes, although the 
antenna's actual height is now at the mid- 
point between antennas. 



Interesting results can be achieved if an 
antenna switch is employed to change 
between any of the three possible antennas 
which are now present — top bay, bottom 
bay, and both bays, each with differing 
radiation angles. This type of arrangement is 
employed at a local station, K9CSW, Here 
two three element duoband quads are 
stacked vertically, with the top bay at 77 
feet, and bottom bay at 37 feet, slightly less 
than optimum for 20 meters, but decent on 
fifteen. Results have been somewhat en- 
couraging, and appear to bear out the critical 
dependency on radiation angle that was 
hoped for. The bottom bay has no doubt 
made such a poor showing due to its close 
proximity to ground, surrounding it by the 
usual city clutter of wires and buildings- In 
addition, differences in excess of two S-units 
were noted between antennas during short 
skip (Sporadic E) conditions. This difference 
was in favor of a high angle over a low. 

Sneaky stacking 

A final method involves feeding the 
stacked antennas slightly out of phase with 
each other, thus raising the main radiation 
lobe. The advantage here is that the 3 db 
that may have been gained by stacking is 
always present, as was not the case in 
switching the antennas themselves. Fig. 9 is a 
theoretical example. For two stacked arrays, 
A and B, 3/4 X or 270 electrical degrees 
apart, best results are achieved when both 
antennas "look" electrically identical and 
are fed exactly in phase, with precisely cut 
equal feedlines. This gives a low main verti- 
cal lobe; for simplicity's sake, well call it 
zero degrees to the horizontal To raise this 
main lobe, the signal must reach imtenna B 
before antenna A, For a rise of 10 \ as 
illustrated, this required the fcedlme to 
antenna A to be longer than that to B by a 
distance D. Using simple trigonuinvtry, dis- 



ax 



OR 270^ < 




Fig. 9. To raise the main vertical racJtanon 
lobe in a vertical stacking situation, antenna 
A must differ in feedline from antenna B by 
a length D. Length D depends upon the de 
sired angre x: here we used 10 degrees. 
Angle y is also 10 degrees: therefore D ts 
equal to tangent 10 deorees times the stack- 
ing spacmg, or .132 A. (See Fig 10* 



82 



73 MAGAZINE 



r 



50 



a 



en 



ui 

00 

o 



25 



20 ^ 



10 











/ 


^ 










1 
i 


^ 
































y 




















X 













I 2 5 4* 

X ADDED TO BOTTOM FEEOLlME 

Fig. 10. Graph of wavelengths of feed line to 
be added to the top antenna in a stacking 
situation (Fig. 9) for raising the main verti- 
cal radiation fobe up to 30 degrees. This 
will only work for 3 A/4 stacking spacing. 



tance D is found to be J32X* To simplify 
things^ this feedline difference has been 
plotted in Fig. 10. Note that this is only 
for a stacking spacing of 3/4 X, 

A similar arrangement is being tried at 
K9CSW, with calculated switch positions of 
10, 15, and 20 degrees, but results are a little 
hazy. Possibly the lobes are simply too 
broad to make a noticeable difference when 
shifted only a few degrees. Quads are par- 
tially stacked antennas themselves, so ele- 
vating the main vertical lobe any appreciable 
amount adds importance to usually insignifi- 
cant side lobes. It's also quite difficult to 
keep two quads looking electrically identical 
for very long* One distinct advantage was 
noted here, however, over simply switching 
antennas. Some types of "city noise" appar- 
ently arrive at very distinct angles; manipula- 
ting the lobes in this manner often resulted 
in noise reduction on the order of two 
S-units, In some locations, this may be more 
valuable than any outgoing signal strength 
additions. 

Conclusion — suggestions and more problems 
The question I've stiU left partially unan- 
swered is exactly what are the best angles? 
BiU Orr's Beam Antenna Book lists the range 
of optimum angle of radiation as in Table 
III. This is apparently inconsistent with 
those findings by Utlaut, (see Fig. 1) who 
found the very best angle to be the lowest 
tried, ,7 degrees, much lower than the 
supposed 7 degree minimum* This was in 
light of the fact that the transmitting an- 
tennas in this case utilized realitively high 
angles (12 or 16 degrees) for main lobes. 
Although only listed for four months, 
Utiaut's signal strength versus time averages 
do show definite seasonal variations; low 
angles did seem valuable during a summer 
month (June or July) when the mle seemed 



the lower the better for the time the band 
was open. The spring months, however, 
pointed out the advantages in ability to vary 
the radiation angle, since higher angles domi- 
nated for much of the ''band open" time. 
Results at K9CSW have varied, but seem to 
agree with this trend. Certainly an accurate 
yearly pattern could be worked out for a 
particular DX path, but the effects of other 
phenomena (sunspot number change, iono- 
spheric storms, north^outh tUts, etc.) that 
may be encountered along the variety of 
paths a DXer is interested in would make the 
game quite involved. 

Band Range of Optimum "Optimum'' Antenna 
Angle of Radiation Height 



7 mc 


1 2 " 40 ^ 


Above 45' 


14 mc 


10--25^ 


Above 40' 


21 mc 


7" 20" 


Above 38' 


28 mc 


5" 14* 


Above 34' 



Table III. Geometrically determined opti- 
mum" radiation angles for the ham bands, (4) 

Another problem was encountered at 
K9CSW. Although signal strength differences 
were sometimes reported in excess of two 
S-units for one angle over another, it was 
rare when a same difference was noted on 
received signal strength- Apparently many 
DX paths are not completely reciprocal This 
is a good thing or we might have to worry 
about accurately matching the DX station's 
vertical radiation pattern, but adds to the 
confusion when trying to decide which angle 
to use to be heard the best. Even in cases 
when signals received on both ends were 
enhanced, the difference was usually not 
detectible unless two-way key down S-meter 
tests were mn. In contests or chasing a 
DXpedition, these key down tests are a little 
hard to come by; the need for some sort of 
system is apparent. Since accurate an^e of 
arrival measurements are expensively compli- 
cated, perhaps only trial and error can devise 
such a system. It's hoped, however, that 
such a system actually exists, for it could 
pay off in great dividends for the serious 
operator, greatly adding to the effectiveness 
of even a modest antenna, 

. , , K9YOE 

Felerences: 1. Davies. Kenneth. Jonospiieric Ra* 
dio Propagation t (Washington, DX. U.S, Govern- 
ment Printing Office, 1965J, Ch. 4. 2. Utfaut, 
W.F. "Effect of Antenna Radiation Angle Upon 
HF Radio Signals Propagated Over Long Distances/' 
Journal of Research of the NBS-Section D, Radio 
Propagation, {Volume 65D, March- April 19611, 
167-174. 3, The American Radio Relay League. 
The ARRL Antenna Book, (West Hartford, Con- 
necticut: ARRL 1956) Ch. 2. 4, Orr, William U 
Beam Antenna Handbook^ (Wilton, Connecticut; 
Radio Publications, Inc., 1955) Ch's. 1 & 6. 



i 



MAY 1969 



83 




wmm 



Crystal Stability iviih VFO Convenience 



Jack Grimes, W4LLR 

Box 1 6004 

Memphis^ Tennessee 58116 



FSK Exciter 



A couple of years of chasing out of 
tolerance ARC-5*s used as vfo's ruled out 
that approach. And anyone who has tried 
building a vfo in the 3 to 7 MHz range will 
testify that obtaining a stability of 20 to 50 
Hz is not the easiest of chores. 

Some thought was given to shifting a vfo 
off frequency during standby, and this ap- 
proach is very workable. 

A better idea, however, was to borrow 
the basic concept from the Northern FSK 
keyer^ which uses a 200 kHz oscillator 
beating against a crystal in a balanced 
modulator. 

One item (available on surplus) which 
seemed ideally suited to the job at hand was 
the sub-assembly O- 1 7- ART- 1 3 A. 

This is a low frequency pto covering the 
range of 200 kHz to 600 kHz in three bands 
and is used in the AN-ART-13. The unit uses 
a 1625 tube, has a very fine, slow tuning 
dial, and is extremely stable. 



(Note: If this pto cannot be obtained, 
don't throw out the idea. A 400 to 600 kHz 
vfo is not difficult to construct around a 
standard 455 kHz bfo coil, and stability 
relatively easy to obtain at this frequency.) 

Since the pto would be the ^'variable" 
portion of the frequency control it seemed 
desirable to use it without modification. 
This could be done by shifting the crystal U 
would minimize the unwanted frequencies if 
the exciter output were one half the trans- 
mitter output frequency. 

Actual construction is straightforward 
and nothing is critical. Most parts may be 
freely substituted within a reasonably wide 
tolerance- The work and testing may be 
divided into four stages- 

1. The power supply may be any 
200 -- 400 V source. 12 v is necessary for the 
heater of the 1625, The other tubes may be 
either 6 or 12 v types, depending on the 
supply. A VR150 and a VR105 or equiva- 



eAC7 
OR 6SK7 
OR 6BA6 



2-6C5 
1-6SN7 



LI *70 TURNS az« 
r FOAM C.T. 



L2-4 TURN LINK 



OMiTLg F6AGT 
STAGE S 
NEEDIJ 




6C5 



fkoa 



-o 

&OMA LOOP 



TAICE OVER 



XMIT RELAY 



Fig. 1, FSK Exciter Schematic 



84 



73 MAGAZINE 




Complete exciter \with pto. 

lent regulator tubes should be used with the 
required dropping resistor (value depending 
un voltage). The 017-ART13 pto should not 
be used with more than 105 volts to 
minimize harmonic output. Once the power 
supply is assembled, the pto should be 
connected and checked by listening for its 
signal on the low end of the BC band, 

2. Next the crystal oscaiator should be 
completed* The only critical parts are the 
feed back capacitors from cathode to ground 
and from cathode to grid. The operation of 
the shift control may be checked by shorting 
across capacitor CI with a screwdriver. 

3. The two-triode balanced modulator 
requires no push pull input of any kind. The 
tuned circuit LI-C2 tunes the output range 
desired. Two separate condensers can be 
used for the sections of C2 if frequent 
frequency changes are not anticipated, 

4. A polar relay is included in the keying 
circuit. With 30 mA bias current supplied 
from the exciter power supply, all that is 
necessary for operation is to plug into the 
local loop circuit. A turn over switch is 
provided. 




Th© 0-17-ART-13 pto, availabfe from Fair 
Radio for $4.00, 



GOING MOBILE 

SUMMER ? 



Before you buy, why not investi- 
gate the low, low price of the fin- 
est transceivers at Dymond Elec- 
tronics. 

Dymond Electronics keeps a com- 
plete inventory of aU the major 
brands ready for immediate pre- 
paid shipment anywhere in the 

USA. 

Your trade is worth more at 
Dymonds. AU inquiries answered 
promptly. 

In Stock for Immediate Delivery 



Collins 



Galaxy 

Swan 

Drake 

Hammarlund 

Gonset 

Hallicrafters 



Ameco 



Yaesu 



• Linear Systems 

• CI egg 

• Vibroplex 

• Hygain 

• Mosley 

• Cush-Craft 

• Regency 

• Astatic 



y^-- 

m. 



l)l(tftOT?<f 

f ELECTRONICS 



Alfred 6. Roach 
W6JUK 



515BLACKSTONE 
FRESNO, CALIFORNIA 93701 

Operated by Hams for Hams 



t^AV 1QCQ 



85 



Mm 







100 nwf 

HI 



LI 



D- 



ici» 



RG 5B 



L4 

4T OVEH 
COLO £NP 



L5 

25T 1126 -r FORM 
( TO TUNE f/Z 



27K 



{[ 



^A«/ 



il 





Fig. 2. 6AG7 Amplifier, 

The function switch allows complete sta- 
tion control with one knob. In standby 
position the cathode of the crystal oscillator 
is lifted from the ground. In the take-over, 
spot, position the exciter is switched on by 
SW2-A while SW2-B shorts out the loop 
across the TU output. Tliis prevents the 
receiver from keying the transmitter (if 
printer and keyboard are in series), and also 
allows a quick return of the printer to lower 
case by flipping the take over switch and 
punchmg the letters key. In the third posi- 
tion the "C" section of SW2 is used to 
control a transmit relay. In position No. 4 
the short across the converter output is 
removed and the transmitter may be keyed 
by an incoming signal 

As with any hetrodyne circuit, care must 
be exercised not to tune up on a harmonic 
or wrong beat. The unit should be set up 
initially with a grid dip meter or absorption 
wave meter The crystal used must be chosen 
so that the fourth or fifth harmonic of the 
pto does not fall on or near the wanted 
frequency. 

By doubling in the transmitter any un* 
wanted is further removed from the tuned 
output of the transmitter. 



SOOMMf 




TO XTAL STAGE GRID 



Fig, 3. Coupling coW to transmitter. 

The average RTTY enthusist will devote 
long hours and careful planning to come up 
with the best possible TLl Then in a rush to 
get the rig on the air will all too often, slap 
a diode shifter on any existing VFO - with 
less than the desired result. 

Or, should he decide to shift a crystal he 
may spend hours grinding the rock to a net 

86 




Fig- 2. 6AG7 Amplifier. 

frequency only to find his shift shy of the 
850 Hz. Not to mention the fact that the net 
frequency may change about the time he 
finally gets within tolerance. 

In fact it was grinding my fifth cri ^tal for 
Air Force Mars net operation in a little over 
one year that made me decide to do some- 
thingj even if it were wrong. 

Some Transmitters may require more 
drive than that obtainable from the balanced 
modulator. An amplifier stage becomes 
necessary. A 6AG7 is a logical choice* The 
grid of this tube is capacitively coupled to 
one side of coil L-1 through a short length of 
RG-58. Two or three turns should be re- 
moved from this side of L-1 to maintain 
balance- (If individual condensers are used 
for C-1, this may be maintained by tuning,) 

The layout of the 6 AG 7 stage must be 
made with care. Some physical separation is 
desirable between the coil L-1, and the 
6 AG 7 tube socket. The output coil, L-2, 
must be placed above chassis, (If L-1 is 
below) with the plate lead going directly 
topside from the tube pin. The 27,000 ohm 
resistor insures complete stability. 

Low impedance output, either from the 
balanced modulator, or the 6 AG 7 stage, if 
necessary, allows the exciter to be located a 
convenient distance from the transmitter. 

A tuned link coupled input coil should be 
used at the crystal stage of the transmitter. 

Of the three FSK keyer units I have built, 
all have proved a pleasure to use. It has been 
found unnecessary to let the pto run all the 
time, as it will be well within tolerance from 
a cold start. And a five minute warm up will 
put you right on the button. The shifters 
have been used days at a time without 
touching the dial on Air Force Mars circuils. 

So if you are having problems with drift, 
setting up and maintaining proper shift, or if 
you are simply tired of grinding rocks, the 
0-17-ART 13 pto shifter may be your 
answer. ^ ^ , W4LLR 

7^ ^flA^6 7lMP 



The First QSL 

Probably it was reading the ARRL quota- 
tion, "A QSL is the final courtesy of a QSO," 
which prompted me to dig into several hun- 
dred old QSL's in order to find out when and 
who started the ''bloody mess/' Unhke the 
story of the "Chicken and the Egg," there is 
no doubt that ham radio came first and that 
the art of QSL'ing was not far behind. 
Apparently it started around the middle 
or the end of 192 L I was operating IIV at 
Bridgeport, Connecticut, at that time and my 
first card came from E. Laufei, 2AQP, who 
reports hearing my signals on October 9, 1921, 
using a one tube regenerative receiver. This 
was followed by a QSL from J. E. Hodge, 
4BY, dated November 10, 192 1, and a report 
from Gerald H. Edison, IB MY, December 30, 
1921, asks, "What is your radiation current?" 
iThese QSL's are aM written on penny post- 
cards with the call letters put on with a rub- 
ber stamp or crayon. The first professional 
print job came to me from 2BRB (now 
W2BRB) and included a picture of the sta- 
tion. It is dated December 28, 1921, and 
most certainly Ed should be considered to be 
among the first of the QSL*ers, 

By 1922 and 1923 the QSL business was 
booming. Fancy printed cards were replacing 
the home-made ones with everyone trying to 
outdo the other in splendor, 

1923 brought the first of the DX cards. 
My first is from W. R. Burne, British 2KW, 
who received my signals on two valves, Sep- 
tember 5, 1923, at 04.10 GMT, so to the 
British go the credit for being the first to use 
GMT on their QSL's, but no doubt their geo- 
graphical location had something to do with 
this* 

Just in case you think the "big boys'* of 
that era were too sophisticated to QSL, you 
are wrong, I have a QSL from 1 AW, signed 
by Hiram Percy Maxim; one from S. Kruse, 
lOA and 9ZN, R.H.G. Mathews. Others in- 
clude John Reinhartz, IQP; Irving VermUyai 
IZE; Dr, Cyriax, 2D1; and, Leon Deloy, 
French SAB. Even the famous IBCG confir- 
med a QSO with me on July 29, 1923. 2B0- 
still going strong as W2B0 sent me a card da- 
ted May 10, 19 23 J and says he is running 20 
watts and using a paragon receiver. 

I suppose we will never know who sent the 
first QSL card but we can pin-point the year 
as 1921 and what a lot of QSL's have been 
exchanged in those forty-seven years, 

C Harold Campbell, W2IP 



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87 



Telephone Beeper 




The following is a description of a tele- 
phone ^'beeper" to be used when recording 
telephone conversations. The "beep" can be 
adjusted to beep every nine seconds as 
required by the Public Utilities Commission. 

Without going into the legality of the 
device, let*s say it can be used to insert a 
beep into the telephone conversation that is 
being recorded, by inductively coupUng into 
the telephone coil. The use of the device is 
visuahzed when recording phone patch traf- 
fic OF recording a telephone message to be 
transmitted at some later time* 

Theory 

A 2N333 and 2N1305 transistor forms a 
multivibrator whose time of beep between 
pulses can be adjusted by a 2 5 OK potentio- 
meter. The pulse stays on for one half 
second, allowing it to drive a 1 kHz oscil- 
lator much better than a saw tooth or 
unijunction type will drive it. When the 
pulse is too narrow the tone is not clear ^ 
thus experimentally the multivibrator was 




: 



+9V 



250K 
VARY TO 
SPACE PULSC 



eeic 



a^f333 L2K 



2^K 



2MI30S 2NI90e 




\buf 

BROWN BEAD 
«47 



£aK 





UIJIVERSAL 
OUTPUT TSAN5F 
JOK PRJ 




TR6A0 S53X 



BLOOPER TO 6e USeO WHEN RECORCHNG 
TCLEPHONE CONVERSATiOMS 



k «^ ^ 



4-Z2 -S 
"22 



Ed Marriner, W6BLZ 
528 CoUma Street 
LaJoUa, California 9203^ 

A brown bead No. 47 lamp bulb acts a! 
pilot light and also as a non-lineaj 
element which helps to sustain reliabk 
pulsing periods. The multivibrator drives £ 
feedback type oscillator using a 2N1306 ai 
the oscillator. This oscillator signal is amph 
fied by a 2N1306 to create enough curreni 
through a coil to generate enough of a field 
to couple into the telephone instrument coil. 

Construction 

The "beeper" is built into an LMB type 
box, 3-1/2" wide, 2" high and 6" long. Foi 
simplicity the parts are mounted on terminal 
strips rather than on a printed circuit board. 

Power is supplied from a 9 volt mercury 
type battery for long life, although, any 9 
volt battery should last a very long time. The 
amplifier's source is 22 volts, which creates 
more current through the coupling coil. 

Many types of coupling coils were tried, 
but an S53X output transformer seemed to 
work the best. The case was pried off and 
then the keeper or end of the core was 
driven off, using a hammer and screw driver. 
It was thought a stronger field could be 
obtained by sawing off one of the sides of 
the transformer to concentrate the field 
between the center and one outside core, 
but there was no difference in the coupled 
signal and it was not worth the effort. 

There are no special precautions in wiring 
the unit except to get the polarity of the 15 
mF condenser in the multivibrator circuit 
correct. If it is backwards, the oscillator will 
not work. An indication that the circuit is 
functioning can be determined by watching 
the lamp blink. 

The spacing of the pulse can be set by 




8eeper to be used when recording telephone 
conversations. 



Note the battery mounting and parts in- 
stalled on terminals* 



88 



1^ hAAir!A'7lKJi 




turning the 250K poteniometer and timing it 
with a watch. A pair of crystal earphones 
can be clipped across the coil if it is desired 
to hear the tone, or the tone by induction 
into the telephone is another way to listen. 
The telephone coil is generally on the right 
side of the telephone as shown in the 
photograph. The transformer can be moved 
back and forth over the side of the phone 
until a maximum coupling is noticed and the 
transformer taped into place. 

The circuit probably has other uses and 
comments might be suggested, but for our 
purpose it has served for inserting a beep 
into the telephone for recording. ...W6BLZ 

(Continued from page 2) 

of the bulging counters full of 194 pots, 5^ 
tubes (guaranteed to light, play), and 29^ 
tuning condensers. 

Sideband came next and finished off the 
old surplus gear that was still working and 
most of the active amateurs made the move up 
to a transceiver,. -commercially made. Lordy, 
it would take a lab of test equipment to get 
one of those things working if you could 
build it. Even the servicing problems were 
getting beyond most of us by this time. How 
many fellows are going to go out and buy an 
oscilloscope and the other choice test gear 
needed to keep the modern transceiver work- 
ing smoothly if they are going to use it only 
for an occasional service job? Virtually none, 

that's who. 

This leaves us in the lousy position of not 
building our own equipment and not even 
being able to service it- Ham radio has come 
a long way. The old timers lament for the 
good old days, but no matter how loud their 
laments, they are buying just like the rest of 
US- Can anything be done about it? I don't 
knowl Does anything have to be done? Has 
amateur radio changed so much that it is no 
longer worth keeping going? 

What are the requirements for keepmg 
amateur radio alive in our country? Let*s 
take a look at the FCC regulations and see 
how we stack up these days as far as the 
purposes of the amateur radio ''service" are 
concerned. 

SUBPART A-GENERAL 
97.1 Basis and purpose. 

The rules and regulations in this part are 
designed to provide an amateur radio service 
having a fundamental purpose as expressed 
in the following principles: 

(a) Recognition and enhancement of the 
value of the amateur service to the public as 
a voluntary non-comniercial communication 
service* particularly with respect to providing 



emergency communications, 

(b) Continuation and extension of the 
amateur's proven ability to contribute to the 
advancement of the radio art- 

(c) Encouragement and improvement of 
tfie amateur radio service through rules which 
provide for advancing skills in both the com- 
munication and technical phases of the art. 

(d) Expansion of the existing reservoir 
within the amateur radio service of trained 
opera tors J technicians, and electronics ex- 
perts, 

(e) Continuation and extension of the 
amateur's unique ability to enhance inter- 
national good will. 

The firsts and presumably most important, 
function is (a) to provide emergency commu- 
nications. I think we can do this all okay. 
There's nothing about building there.. For 
that matter, our commercial transceivers are 
vastly superior to home made equipment on 
several counts... easier to use... less down time 
.-.anyone can use it.. .compact, etc* Old timers 
will teU you stories about the olden Field 
Days when fellows tried to tune and use some- 
one else's rig and the troubles they had. My 
six-foot rack has been replaced by two small 
desktop boxes. And with about one amateur 
for every 800 people in the country we can 
provide emergency communications just a- 
bout anywhere anytime. I think we should 
get a good high mark on (a)- 

Considering (b), it is difficult, of course, 
for even the above average amateur to try 
to compete with the well financed research 
laboratory for most development work. We 
can still compete with them when it comes to 
major break-throughs. Labs cannot possibly 
afford to spend a lot of money on something 
that does not have virtually a 100% chance 
of succeeding. We can. Fellows like Frank 
Jones, Bill Hoisington, Sam Harris, Bill Ashby 
and many others are doing work that is in- 
valuable to our society,. .work that few labs 
would ever support. It is too bad that there 
are so few really outstanding men like this, 
but then, even in the past, there were only a 
small handful that made real contributions. I 
suspect that amateur radio is as valuable as it 
ever was in this respect. 

(c) is very interesting, Verrry. Obviously, 
our incentive licensing rule changes reflect 
this aspect of the purposes of amateur radiOp 
But have our rules really kept up with the 
technical end of things? Let us take another 
look back into our past at this time. 

The first amateurs used the Morse Code for 
communications. It was considered difficult, 
at best, to modulate a spark transmitter, so 
code was the answer. Then came CW and the 
invention of the modulator, giving us AM, In 




MAY 1969 



89 



B 




the 20'sand 30's the phone transmitters were 
considerably more expensive than CW rigs 
and a lot more difficult to tune, with the re- 
sult that most amateur operation was via CW. 
But, as soon as phone was available the hams 
started using it and the percentage of phone 
ops grew steadily. Most operators preferred 
to talk rather than whistle and they changed 
to ptLone as soon as they could afford it. 

Sideband completely broke the back of 
the CW holdouts. Their complaints that CW 
could get through better than phone or that a 
CW rig was much less expensive than a phone 
rig fell apart. Sideband, they found, could 
get through just about any time that CW 
could! And the Heath $99 SSB transceiver 
forever stilled complaints about cost. 

There are still a sizable number of ops that 
use CW because they enjoy using it, but few, 
except Novices, use CW out of necessity. With 
the percentage of CW operation dropping 
year by year, many have wondered just why 
the FCC added the 20 wpni requirement to 
the Extra Class license. 

Modern comniunications techniques would 
seem to put emphasis on things hke RTTY, 
facsimile, slow scan television, narrow band 
television, time sharing of channels, and other 
developments rather than harking back to 
our early days and our most primative mode, 
The FCC, to the contrary, has been decidedly 
backwards in handing down favorable rules 
for RTTY, facsimile, television, etc. Amateur 
development of these modes has been haras- 
sed and impeded by the FCC rather than 
helped^ as per (c). 

Part (d) calls for trained operators, tech- 
nicians and electronic experts. We are con- 
centrating more on trained operators these 
days than technicians. But, with some 
10,000 of us active on the VHP's and a sim- 
ilar number working with RTTY and other 
advanced modes of communications, we are 
not doing too badly in the expert department. 

Good win? With phone contacts as sim- 
ple as they are today tens of thousands of DX 
operators can talk and make friends with fel- 
lows all over the world. A few simpletons 
yelling break-break, or calling doggedly on a 
DX frequency can create ill will, but for the 
most part, ham radio is a friendly world com- 
munity. A recent report of the Stanford Re- 
search organization showed that, dollar for 
dollar, radio amateurs achieve more good 
will than short wave broadcasting... by a large 
margin. 

We might try to curb our penchant for do- 
nating money to expeditions too. These 



often bring terrible ill wiU for us from abroad. 
The big problem is this: since the DXer is 
doing the job for money, he is very apt to 
by-pass a lot of formalities and tread heavily 
on toes in order to get on the air. One DXer 
went into Jordan a few years back and went 
on the air without a proper Bcense. The re- 
sult was that ham radio was finished there 
from then on. 

All in all, when you look over the FCC ba- 
sis and purpose for amateur radio, we seem 
to still, in spite of all the changes that have 
come about,, be well worth our salt. Perhaps 
those that are calling for a return to building 
should take a look at the balance sheet. 

My own feeling is that building equipment 
is a lot of fun and I intend to run every con- 
struction project in 73 that I can get my 
hands on. Of course, I will tend towards 
pushing the newer modes such as TV, RTTY, 
SSTV, FAX, FM, and the like. We have a 
thousand or so hams that spend their hobby 
hours building equipment. Few of them ever 
get on the air for more than a short test of a 
new unit... then the parts go back into the 
junk box and the next project is underway. 
These are the fellows who provide us with 
most of the original constructions articles... 
this is why you keep seeing the same calls 
over and over in 73, 

It is important for us to do everything we 
can to see that we constantly have new ama- 
teurs entering the hobby. A certain percent- 
age of these newcomers will turn out to be 
builders... others will go for new modes. ..and 
a very few will get some sort of weird idea 
for a radical change and spend years working 
on it •..and they just might succeed. I am 
reasonably sure that it won't be long until 
someone makes a gigantic breakthrough into 
another form of communications which will 
make radio obsolete. It could well be one of 
the Novices who will get his ticket this fall. 

What do vow think? ...Wayne 

Recent Visits 




90 



73 MAGAZINE 



F 



Sam Harris, W1FZJ/KP4 runs the receiv- 
ers down at the world's largest dish in Areci- 
DO. Sam is active on 75 M in particular, work- 
ing DX along the low end of the band. He is 
ilso working on a mimature Arecibo dish at 
home, a few miles from the Big One. His 
75 M and 40M antennas are hanging from the 
three ''haystack" mountains that surround his 
QTH. 



worked her by now, Helen has an incredible 
card index file of the thousands of stations 
she has worked on six meters so far. Note 
the 50 or so notebooks over the operating 
position! 





Helen Harris, WIH0Y/KP4 keeps her ear 
fastened to the receiver on six meters all day 
every day. She doesn't miss an opening if she 
can help it. If you're on six you've probably 



Dick Spenceley, KV4AA is alive and well 
on St. Thomas. Dick is another who got off 
the DXCC treadmill when crossed up by 
Miller, He still keeps at it, but for fun now 
instead of blood- Does Dick have the world's 
best fist? Many think so. 

-..Wayne 



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MAY 1969 



91 



n 




Kilowatt 



Dummy Antenna 



. . Cheap 1 



f 



Allan H. Matthews, WB2PTU 

R. a 01 

Waverly, New York 14892 



This article describe^i a dummy antenna 
capable of handling one kilowatt, to be built 
at a cost of under S4.00, In my case it cost 
SU3, but that was with a junkbox. 

In a back issue of 73 (where else?), there 
were some 100 ohm, non-inductive resistors 
advertised by Mendelson Electronics, 516 
Linden Ave,, Dayton, Ohio, I ordered two 
of these at 50^ each for my dummy load* 
When they arrived, they were 3/4 inch in 
diameter and 6 inches long, with both ends 
tin plated. I do not know the power rating 
of these resistors but they are more than ad- 
equate for our use. This unit will handle 
over 1 00 watts PEP with no oil. 

The photograph tells the story. The top 
and bottom plates were cut to dimension, 
punched and drilled first- Next the resistors 
are fitted into the outside holes of these 
plates and soldered into place. I used l/8th'* 
double copper clad glass epoxy board and 
soldered the resistors to both sides of the 
board. Next run a heavy wire down through 

100 OHMS 




005 




■A/SA^ 



7h 



100 OHMS 



W 



Ih 



/\ 



0-10 MA 

■€> 



e 




* ^ AJA3^PJLi..a-PV«WULP ■ ■"rrilT *'lll^ 11 II 



the center hole of the top plate and into the 
small hole of the bottom plate. Solder it on 
both sides of the plate. Center this wire in 
the top plates center 3/4" hole. 

The next step involves a gallon paint can 
which can be purchased empty and clean at 
many paint stores for about 504- Punch the 
top of the can for a coax fitting, drill the 
holes to mount the unit inside the can and if 
you want a relative power output attach- 
ment, drill holes for the feed -thru terminals 
you wUl use. Also, drill 1 extra 1/16'' hole 
in the top of the can. 

Mount the top plate hanging down from 
the top of the can on 3/4" metal stand-offs. 
The resistors will clear the bottom of the can 
nicely at this height. Now jnount your coax 
connector, your feed-through terminals and 
the other components in place and solder 
them. Run a couple of copper braids, (coax 
shield) from the top plate to the top of the 
can and solder them well on both ends. 
They will help to provide a low impedance 
ground path. The diode I used was of doubt- 
ful ancestry, but a 1N34A shoulu do the 
trick. This relative output meter circuit 
allows use of a fairly heavy meter, dependent 
upon the power tif the transmitter and the 
frequency of operation. A variable resistor 
across the meter will be an aid. 

Now go to the power company and 
scrounge a gallon of transformer oil or fill 
the can with mineral oil, leaving about 1 and 
1/2" of space at the top of the can. Do nor 
use motor oil!! The extra 1/16" hole? Oh, 
that is to relieve pressure as the oil heats up. 
When not in use, plug it with a match stick 
or small bolt. Well, there it is, a kilowatt 
dummy antenna at a price everybody am 
afford, 

,.AVB2PTU 



f 



92 



73 MAGAZINE 



LRL*p66 antenna 66' long, so mtu iom 



Power rating 2 Kw, P,E.P. orov*r on 80, iD^ 1 3 
Ofi 20 ond 10 1 Kw, P,E.P, Tronimitttr inpyf 





6 

pmcE 

In Cd 
USA. ppd. 



» r 

Rt. I 
Bud. I 



OPERATES ON 5 BANDS AlTTOMATlCALtY 

1, Loading eaila for 80 & 40M doublet operation 

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Owantboro, Kantuchy 42301 




One that Didn't Work Out 

Don't misunderstand me. The home-brew 
:oax switch I'm about to describe works fine. 
it just cost more than it should have, and it 
joesn't do quite all that a commercial unit 
does. If the purpose of home-brewing is to 
save money while producing gear equal or su- 
perior to commercial products, this project 
qualifies as a failure. Still, it may be of inter- 
est. 

First, you take a cat food can -one of the 
little ones that contains the so-called ''gour- 
met" cat foods. Open it and feed your cat 
the contents. (You Jo have a cat, don't you?) 
Then wash it— wash it very well If you don't 
you'll have a very smelly coax switch! 

Now, mount six SO-239 connectors equal- 
ly spaced around the outer wall of the can. 
(Use the single hole mounting type if you 
can,) Drill a hole exactly in the center of the 
bottom, mount a six position ceramic switch 
with 60 degree indexing, and line up the con- 
tacts with the sockets. Note that in one pos- 
ition, there will be no connection, since one 
of the sockets serves as the input to the 
switch • Wire it up using short lengths of #1 2 
wire. Cut a disc of flashing a little larger than 
the diameter of the can, and seal up the back 
by laying a bead of solder between the rim of 
the can and the flashing. 

If you buy everything new, the switch will 
cost you five or six dollars. It doesn't ground 
the system in the ''off position, and it won't 
handle a kilowatt- For about five dollars 
more, you can buy a switch that does. How- 
ever, crosstalk is low in the home-brew 
switch, and if you have enough coax connec- 
tors and a suitable switch in the junkbox, it 
may be up your alley. Works fine for switch- 
ing between antennas, dummy loads, trans- 
vcrters, etc. If your junk box doesn't contain 
the necessary parts, take my advice- go buy 
a commercial unit. 

There's a moral in this somewhere, ..some- 
thinizabout the point of diminishing returns? 

Bob Grenell, W8RHR 



*■ 



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Dept. H. 196-23 Jamaica Ave, Hollis, N.Y, 11423 




"OK, so tomorrow yo" 9^* your own 
transceiver!" 



MAY 1969 



93 



J 




Mini— Bomb 



Bill Brown W<t,SYK 
28 Marine Lane 
Hazelwood, Mo. 



After many attempts to design a two 
tuber (4-lOOOA or 8166) on a standard chas- 
sis (13x 17), I gave up in despair and went 
to a larger chassis which was 15" x 26" x 6" 
deep. An article was pu])lis]ied in the May 
issue, 1965 called the "Big Bomb". I know 
of more than 30 Hams that are using this 
design. 

The smaller rig got started one afternoon 
after finding a very small ceramic vacuum 
capacitor. After two da\s on the drawing 
board I finally got all the parts laid out wdth- 
out overlapping. Some features that might be 
of interest are as follow: Both plate and load- 
ing capacitors were mounted on 3" x 5M" x J2" 
Machine aluminum blocks, which will pre- 
vent current losses and \\'ill add to the liigli 
efiicienc\'. Checks proved efficiency as high as 
72%. 1 would like to call your attention to 
the high voltage feed-thru. These are home- 
made out of 1" round teflon extending 1" on 
each side of chassis. Breakdown was better 
than 30 K. Plate coil for 20 meters was 
formed on quart bottle of TANQUERAY gin 
(dia. 3%"), length was 5^", (Tubing %" 
used). The design of the "Mini Bomb" is 
such that parasitic chokes are not necessary, 
and this final was checked for this with volt- 
age better than 7.5 K. Chassis was chrome 
plated to prevent rusting and for appearance. 



94 




Since tlie tubes are in the front and cen- 
tered on the chassis; a 6" x 9" cutout was 
made to view tubes. This cutout is BMs" 
from the bottom of the panel, which is steel, 
and nW high. Two meters (3^") were 
placed above the cutout. The plate meter is 
0-1.5 amp. and the output meter is 0-1 mA 
with a 0-10 rf amp. scale being used. The 
large 3" Groth counter Dials rounds out the 
Panel. 

This final is housed in a 6IV4" cabinet 
with 24" depth, in order to make room for 

73 MAGAZINE 



AflT. 



r 



,01 
IK 




IIOVAC 



+ KV. 



rj'FROMT 



METER 

LEAD 
HOLE 



±3r 




SWB* 



LOAD ^^F& CON D. 

BLOCKS ARE 3' K 5 l/^*^ 1/2* AL 



I 1/2" 



RF CHOICE 



21/2' 



1 




1/4" 

HV FEEDTHRU 



VAC 
CO NO 

1V2- 



^- 



9/16 



a 



5 1/2' COIL STAfJD OFF 



— I" 

2 1/2' 
t 



MINI-B0M8 CHASSIS LAYOUT 



19'- 



171/2' 
Ofl < 

LARGER 



6 1/2 




CENTER- 
METER HOLE 



€ 1/2' 



5'- 



9" 



5M2* 



TuaE CUTOUT 



5'- 



6 \M* 



PANEL LAYOUT, MtWiaOMS 



the blowers. The panel below is used for the 
''wheeT which is a Superior 28 amp. power- 
Stat. The bottom panel is used for power 
supply, ac switches and pilot lights. 

Power Supply 

A real lieavy duty power supply can be 
built for less than one hundred dollars. The 
plate transformer was purchased from the 
local power company for less than 20,00. 
The rating is 5 KVA @ 7200 volts ac. This 
will give around 6500 volts dc under load 
for the highest voltage. I like to operate with 
a voltage of 3700 using 100 watts drive from 
a Collins 32S-L Two 550 mA UTC chokes 
are used in the negative lead. These chokes 
are in series with the swinging choke, fol- 
lowed by the smoothing choke. Solid state 
silicon rectifier were built up by using 
48 (1 amp @ 1 K. Diodes) Oil capacitors 
were purchased from the power company 
also, at tlie rating of 2500 AC @ 7-5 mfd. 
Four units are being used giving a total of 
30 mfd better than 7000 VDC at a price 
$3,00 per unit, A bleeder consisting of seven 
10 K @ 200 watts resistors in series finishes 
the power supply. In closing, I have been 
using this heavy t\^e of construction for tine 
past 11 vears without a single break-down 
of any part in this rig, Good DX-ing. 

. , , W0SYK 



MAY 196? 



95 



DX 




rom 



mg 

DL Land 



This is an American's view of what it^s like 
to operate an Amateur Radio station in Eur- 
ope. Tills is by no means a unique achieve- 
ment-many hams who are in the Armed 
Forces are transferred to Europe each year, 
but I have never seen an account of their ex- 
periences in print. For those who are coming 
to Europe in the near future, this may serve 
as a guide of what to expect. For others who 
will never have the opportunity to sign a 
"'DX'' call, 1 hope tliis will be interesting, 
I received notification of my assignment 
to Germany in January 1967, with instruc- 
tions to report during the month of April- 
Along with finding out all I could about the 
base to which 1 would be assigned , I set about 
trying to determine what would have to be 
done to set up a ham station. Since all I had 
read concerning reciprocal licensing stressed 
contacting the agency responsible for the is- 
suing of licenses in the country to be visited 
prior to arrival, I wrote to the Bundesminis- 
terium in Bonn, requesting information and 
instructions. 1 received a reply very quickly 
(via Air Mail), and the gist of the letter was 
that I would liave to go through the Military 
Affiliate Radio System, since they serve as a 
liaison with the German licensing officials 
(the Deutsche Bundespost). After 1 arrived 
in Germany, things were a bit hectic, bb in 
any move, but I managed to get to the MARS 
station on the base and fill out the necessary 
forms, and then a helpful clerk made the ne- 
cessary photocopy of my Stateside license 
(for proof of Ucense class), and the paperwork 
was set in motion. Red tape being what it is, 
it was about a month before 1 got my license. 
This cost $9,75 for one year- we get off cheap 
in the States! 

Now to get on the air. I had been busy 
with moving Into an apartment and getting 
settled, and so far had not erected any an- 
tennas, so I strung a twenty meter dipole 
across the apartment. My first contact was 
withlA^^ AC, 5-7-9, both ways. Not too bad 
for my haywire set-up, but 1 definitely need- 
ed something a bit better. After examining 
the situation I decided that to keep on good 
terms with the landlord (who lived immediat - 
ely below^ us) and still radiate a signal, Fd have 



Joseph D, Burnett. Jr.. DL4BR 
26 AEMS, CMR Box 4086 
APO New York 09009 

to hang something up in the attic. There are 
quite a few people in Germany who have 
large yards with lots of nice trees, bui the 
majority of the people build their houses 
close to the street and turn the back yard into 
a garden. The housewives spend a lot of 
time keeping their houses and yards spotless 
and beautiful, and the gardens are right out 
of a picture. Our landlord and his wife were 
of the majority, and I wasn't sure how they'd 
react to an ugly pole sticking up out of that 
picture-book garden, with wires and cables 
hanging all over the place- So, what with the 
language barrier and a shortage of apartments 
I took the easy way out. Looking at it in 
retrospect, I tliink that if I'd brought a beam 
and tower here with me the landlord would 
have been more than happy to let me put it 
up, and perhaps even helped me with the in- 
stallation, i have yet to find anyone who has 
had problems with a landlord here in Ger- 
many, except those who have made a nuisance 
of themselves with loud parties, etc. 

Now, I had antennas for ten, fifteen and 
twenty meters (or indoor, air-cooled dummy 
loads, if you prefer), and I started operating. 
I was a little worried about the language bar- 
rier on the ham bands, but 1 needn't have 
been. English seems to be an almost univer- 
sal language among hams. Naturally there 
are some mistakes in pronunciation or word 
usage, but the thought gets across, and that^s 
what counts, I stayed in the DX bands at 
first, since that's where I expected to find 
hams who spoke English, but after taking a 
German conversation course I braved ^^-5 
MHz CW, using a matchbox and a huiiK of 
wire; lo and behold, the same old abbrevia- 
tions were in use there, and I felt at home al- 
most at once. Unfortunately, too many of 
the QSO^s I've had were of the *'Hello, good- 
bye" type, but there were a number of rag- 
chews both on CW and phone something 
you don*t have a chance to do very often 
when you work a DX station from the States. 
The regulations governing amateur opera- 
tion herein Germany are much the same as in 
the States, except for a reduced maximum 
power input and some of the frequency allo- 
cations. We are allowed only 500 watts dc 
input to the tinal; but that's not too bad, 
because there isn*t the QRM level here that 
there is in the States. However, on eighty 
and forty the popular Heath single band trans- 
ceivers are useless without modification (as 



96 



73 MAGAZINE 





are some of the other transceivers). The DX 
bands are the same as in the States, but forty 
is only one hundred kilohertz wide, and 
eighty is three hundred kilohertz wide (7.0- 
7.1 MHz and 3,5-3.8 MHz). There is no of- 
ficial CW/phone separation of the ham bands 
here, but by gentlemen's agreement the lower 
one hundred kilohertz of each band is set 
aside for CW use; the exception being on for- 
ty, where the lower fifty kilohertz is usually 
CW only, but sometimes this varies with band 
occupancy. 

TVl is not an overwhelming problem here 
as it occasionally is in the States. For one 
thing, the TV stations are controlled very 
closely, and have been set up for optimum 
coverage, thereby reducing or eUminating 
^'fringe * areas. In my area the channels in 
use are 12^ 14, and 40; and to get a harmonic 
into one of these^ youM really have to work 
at it. Fundamental overload is still a problem, 
but one that can be fairly easily corrected 
with a little cooperation* Even quiet hours 
are no great hardship, as the TV doesn't come 
on untU early aftemoonj and usually signs off 
before midnight. 

Our AC power is 220 vac, 50 Hz, and it's 
fairly well regulated. There are transformers 
available commercially to step this down to 



110 vac, and with few exceptions any gear 
designed for 60 Hz wHl work all right on 50 
Hz without excessive transformer heating. 
Most of the better American manufacturers 
are providing export models of all their gear 
noWj so if you're concerned about possible 
equipment damage this might be something to 
look into. I work in a test equipment repair 
and caHbration facility^ and to date the only 
problem we've had with transformer burn- 
out (due to Une frequency) has been with 
some poor quality imitations of Tektronix 
equipment* 

My pet peeve about my tour here has been 
(and is) QSL's, and the lack of them in my 
mailbox. I get a card out to each station 
worked J with one or two exceptions due to 
lack of address information, but to date^ my 
return rate from W/K stations is just above 
fifty percent. I'm sorry to say that the return 
rate from DX stations is somewhat lower, but 
perhaps they have postal problems Fm not 
aware of. 

This is not a complete picture of the Amer- 
ican ham in Europe by any stretch of the im- 
agination, but I hope you found it entertain- 
ing. If there are any questions, drop me an 
SASE, or look for me when the skip is good, 

-..DL4BR 




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MAY 1969 



97 




1 
I 




m^^ 



KatashiNose,KH6IJ/l 
10 Cambridge Street 
Belmont, Mass. 02179 



p 



On the Use 

Phonetics 

in Pileups 




If you are among these fortunate enough 
to have a call sign like W6AA, you won*t be 
interested in the rest of this article, but if 
you have one like WD2BJB, you may be 
interested to know what the DX'er on the 
other end of a DX contest pileup thinks of 
you if you say *' Whiskey, David, the number 
two, *D' as in Denmark, *J' as in Japan, and 
*B' as in Boston." 

Some time in the nostalgic past when all 
call signs began with a "W" or with no prefix 
at all, it was an easy matter to decipher call 
signs* Today, with so many prefixes to 
choose from, we seem to have gone over- 
board in our phonetic frenzy to get call signs 
across. 

Phonetics are to clarify, not to confuse, 
yet frequently we are apt to accomplish the 
opposite by employing certain techniques- 
In a hot contest or pileup, the object is to 
get as much information across in a short 
time as possible. Frequently in a contest, the 
contact is over while a slow caller is bliss- 
fully repeating his phonetics. 

There are two things wrong with "Whis- 
key David, the Number two, Denmark, 
Japan, Boston/* For one thing there are too 
many bits of information to remember, and 
secondly, remembering the proper order 
puts one more burden on the DX station. 

Let's put yourself on the receiving end of 
a pileup. The important part is *'DJB," the 
rest can be filled in at leisure after the 
contact has been estabUshed. What would 
you do if you were a WB2 and you heard the 
DX station announce, "The WB2 what was 
your call?*' Immediately ail WB2's are com- 
pelled to answer. However^ "The station 
with call like DJB" immediately identifies 



you unless there happens to be a BJD, BGD, 
BJB, or some other phonetically similar call^ 
a rare coincidence. If you go back in the face 
of such positive identification, you would be 
ostracized* 

The important thing is to get at least two 
letters of your suffix across. If the DX 
station has any savvy at aU, he wiU pry the 
rest of the information from you at his 
leisure. When the DX asks for a fill, give him 
only the information he wants. He asks for a 
fill because of QRM and not much else- 
How effective is "Denmark, Japan^ Bos- 
ton?" After about 3000 contacts, the DX*er 
is a pretty weary fellow. After hearing 
"Denmark, Japan, Boston" he is liable to 
mutter to himself, "Now was that Japan, 
Boston, Denmark or Boston, Denmark, 
Japan?" By using phonetics you give him the 
extra task of trying to remember which 
word came before which. The order may be 
trivial to you, since you have practiced it 
many times, but the DX operator has heard 
that combination for the first time and he 
lias to remember the order. 

Just plain "WD2BJD*' is apt to be more 
effective because it is easier to remember for 
the DX'er. He might have gotten it as 
"WB2BGB" but what does it matter? You've 
nailed him and can now correct him at your 
leisure. Better still you should say 
''WD2BJD, Baker John Dog" and not the 
reverse order, WD2 Baker John, Dog, 
WD2BJD, The worst of course is "William 
Dog, the number two. Baker, John, Dog.** 
The DX*er now has to remember a Baker, 
two dogs, a John, a William and a two 
floating around some place and must place 
them in proper sequence* No wonder he 
mutters to himself. 

Stick to plain WD2BJD, no phonetics 
until asked for^ If the DX*er goes back to 
only those who give phonetics, he probably 
won't be a winner for his country because he 
is taking too much time per contact. 

Going to the other extreme, I have heard 
something like "DJB, DJB, DJB" given with 
no prefix — "no nothing." This is especially 
pathetic to hear when he is the only one left 
calling after everybody has gone to the 
listening cycle. Giving the phonetics of the 
DX station is downright insulting. It is 
tantamount to telling the DX he doesn't 
know his own call. 

"What's your number again?" may not be 
correct grammatically, but it is more effec- 
tive than "I would like to have you repeat 
your number,'' Note "what is" (he wants 






73 MAGAZINE 



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something so get set), '^number" (it*s my 
number he wants), ''again," (he means re- 
peat). The sequence is **get set" "for the 
query" "reinforce.'* This technique also 
works for copying high speed CW.* Note 
that in "I would like to have you repeat my 
number," the only part that carries infor- 
mation is **repeated number" 

"William David Two Dog John and a 
Baker" is just as bad as "Kay Nine Dog and a 
King" (K9DK), The DX is apt to caU you 
K9DNK, As my friend K4Ii says **If I send 
K4II "k" meaning "ar" on CW, Vm done for 
because they will insist on calling me K4IIK." 
This is just as bad as catling KH6IJ, K5B1J, 
or KS6IJ on CW. I just can't shake them 
loose once the imprint is fixed, but on 
phone thanks to phonetics^ corrections can 
be made. 

Getting attention in a pileup calls for the 
skill of a seer. One must be able to place 
himself in the framework of the DX*er and 
be able to outguess the competition, and still 
not arouse the ire of the DX'er, 

If you want to put these ideas to a test, 
come to Hawaii and operate in a DX contest. 
As for me, I don't care about fancy foot- 
work, I just go back to the first caller I can 
make out who signs early. 



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MAY 1969 



99 



1 



Getting Your Extra 
Class License 



Part IV — Radio Waves 



f 



The whole purpose of radio is to com- 
municate, and to do so requires that infor- 
mation be transmitted from one place to be 
received elsewhere. The difference between 
radio and other forms of communication is 
that, in radio, we transmit this information 
over "radio waves" rather than by means of 
wires or the printed page. 

To use radio for communication we must 
have some knowledge of the way in which 
radio waves work, and so the Extra Class 
license examination includes a number of 
questions to test your knowledge of radio 
wave propagation. 

In fact, it includes too many such ques- 
tions to cover adequately in a single install- 
ment of this series. This month we'll look at 
the general principles involved, and some of 
the more unusual aspects of VHF propaga- 
tion. We'll handle the following questions 
from the FCC study list: 

48 < How do the directivity of an unter- 
minated "V" antenna and a par^itic 
beam antenna compare? 
58. What are aurora-reflected VHF sig- 
nals? If such a signal is heard, what 
does it sound like? 
67. What constitutes a parasitic antenna 

element? 
71. List some different types of beam 

antennas. 
76. What determines the skip distance of 

radio waves? 
As usual, we'll extend the scope of these 
questions to cover the subjects more fully. 
For a start, we'U examine the whole problem 
by asking '*What Is Radio Communication?" 
We will find, while exploring that subject, 
that signals are both radiated and reflected 
in the process of being used to communi- 
cate. 

Our second and third questions will look 
in more detail at reflection, by asking first 
"How Does Signal Reflection Occur?^* and 



then "How Does Reflection Affect the 
Signal?". The answers to these two questions 
will include the unusual VHF effects, and 
will also help us meet the final two ques- 
tions. 

Our final two questions will bring us into 
the area of signal radiation: "How Is a Signal 
Radiated?'' will introduce the subject of 
antennas in general; "How Can a Signal Be 
Concentrated?'* will focus our attention on 
directive antennas. 

While we'U get no farther in this month's 
instalment, future discussions will extend 
our study of antennas in the same direction. 

All set? Let*s dive in. 

What Is Radio Communication? It may 
seem an overstatement of the obvious to 
proclaim that the whole purpose of radio is 
to communicate — yet many of us are so 
involved with the purely technical aspects of 
radio and electronics that we tend to lose 
sight of this basic fact For this reason it's 
worth while to stand back at this point and 
try to find out just what is involved in 
communication by radio - or "radio com- 
munication". 

Let's try to find out what is involved by 
doing some "word substitution". What we 
want to know is simply "What Is Radio 
Communication?" If we can substitute other 
words or phrases for the words "radio" and 
"* communication", we may have a meaning- 
ful answer. 

We'll tackle the hard one first — what can 
we put in the place of "communication"? 

This is hard because the question of what 
constitutes communication has been stump- 
ing the experts for years, and promises to 
continue doing so for some years to come. 
About aU that they agree on is that com- 
munication involves a "transfer of infor- 
mation" — so let's tr>^ that on for size. 

"Radio transfer of information" stUl 
seems to make sense although it doesn't tell 



p 



100 



73 MAGAZINE 



us much more. Lcfs use that and try to keep 
going along this route. What can we put in 
the place of "information'*? 

Some 20 years ago^ fortunately, Claude 
Shannon found a good answer for that one. 
He defined information as "a selection from 
a set of possible choices", and went on to 
define it more precisely as a reduction in the 
uncertainty of the selection. However when 
we plug in Shannon's definition of infor- 
mation the result looks more like a govern- 
ment directive than like any meaningful 
explanation. Lefs try again, using Shannon*s 
idea but not his words. 

The simplest possible amount of infor- 
mation about anything is the mere fact that 
it exists, or does not exist. This is an 
all-or-nothing choice with no alterna- 
tives — and we make use of it any time we 
send a message using CW. The carrier is 
either there or it is not, and we interpret the 
pattern formed by its presence or absence 
over a period of time into characters of the 
alphabet wMch spell out the message* 

Following this line of reasoning, tiie 
carrier is a radio wave and a radio wave is a 
form of energy. It's not unreasonable to say, 
then, that information can consist of a 
sequence of energy patterns. It's not even 
unreasonable to assume that it always con- 
sists of such a sequence of energy patterns, 
because an AM signal or even TV is also a 
sequence of energy patterns — just much 
more complex than the simple on-or-off of a 
CW signal. 

And plugging this in gives us the phrase 
**radio transfer of a sequence of energy 
patterns", which doesn't seem to be too far 
out although it does tend to sound more like 
engine eiingese than like English, Let's see 
what we can do about that. 

The word "transfer" always implies a 
"from-to" relation; that is, it means a 
movement of something from a source or 
transmitter to a target or receiver. Let's use 
this fact to modify our phrase even more: 
"radio movement of a sequence of energy 
patterns from a transmitter to a receiver" is 
the result^ and it sounds more like English if 
we turn words around a little to say "move- 
ment of a sequence of energy patterns from 
a transmitter to a receiver by means of 
radio", 

What*s more, this expansion of the simple 
phrase "radio communication" is beginning 
to look almost like a definition, which is 
what we set out to find! 

About all we have left to do to it is to 



expand the word "radio" and we may have 
our answer. 

The physicists tell us that any energy can 
be moved by two routes — conduction and 
radiation. Conducted energy moves along 
some physical "conductor"; direct current 
flowing in a copper wire is an example of 
conducted energy, and so is Ught flowing 
through a polished plastic rod* For that 
matter, the heat reaching the handle of a 
skillet gets there by conduction too. 

Radiated energy, on the other hand, 
moves directly through space without bene- 
fit of a conductor. The light and heat from 
the sun are good examples of radiated 
energy. So is the rf output of any trans- 
mitter once it leaves the anteima. The word 
"radio" is, in fact, simply an abbreviation of 
the word "radiate"! 

So we can define "radio communication" 
as being "movement of a sequence of energy 
patterns from a transmitter to a receiver by 
means of radiated energy". This gets us the 
answer to our first question, but there are a 
few points to clear up before we move on to 
the second. 

For instance, the "transmitter" in the 
definition we have just developed is not 
what we generally mean when we use the 
word. In this definition, a *' transmitter" 
includes the entire setup from operator and 
mike or key, through the transmitting equip- 
ment, to the antenna. Similarly, the word 
"receiver" in the definition indudes the 
receiving antenna, receiving equipment, and 
finally the receiving operator. After all, 
communication is established only when 
something gets from one human brain to 
another — you can't do much communi- 
cating with a beacon or code wheel! 

And the use of the words "radiated 
energy" in the definition doesn't mean that 
some conductors aren't involved too; the 

point here is that the m^gor part of the 
transfer is done by radiation. We all know 
that any radio equipment is full of wires. 
The story is told of a British dowager in the 
early days who, upon being shown a "wire- 
less" station, asked "Why do you call it 
wireless? I've never seen so many wires 
before in my life! 

In fact, communication by radio involves 
the use of both conducted and radiated 
energy. The transmitting equipment origi- 
nates the rf energy and puts the sequence 
of energy patterns into it, and all during this 
phase the energy is conducted by our wires 
and feedlines. If any of it does radiate at this 



' 



MAY 1969 



101 



stage of the game, it's a major problem! 
That's what shielding is ail about. 

The antenna is the bridge between con- 
duction and radiation. At the transmitter, 
the energy is conducted to the antenna, and 
radiated from it. At the receiver, the antenna 
picks up the radiated energy, and the energy 
it receives is conducted into the receiving 
equipment. 

So long as our rf energy is being con- 
ducted, it follows most of the normal rules 
which apply to dc and low-frequency ac 
(with a few exceptions such as skin effects). 
When it is radiated^ the special rules which 
apply to radiated energy get into the act 

It might appear most logical to move 
from here directly into our examination of 
the bridge between conduction and radi- 
ation, the antenna. However, action of many 
types of antennas involves the rules of 
radiated energy rather than those of conduc- 
tion, and so is easier to comprehend with a 
knowledge of these rules. For that reason 
we'll examine the rules of radiated energy 
next. Then weTl move on to look at the 

antenna situation, 

Hovo Does Signal Reflection Occur? Re- 
flection of a signal is just one of two effects 
which occur when radiated energy meets 
anything. To find out how a signal is 
reflected, we must examine the way in 
which radiated energy interacts with any- 
thing it meets. 

It's easiest to understand by keeping in 
mind that light is also radiated energy; any 
rule followed by an rf wave must also be 

followed by light, and any rule obeyed by a 
light beam must also be obeyed hy rf 

It's also important to keep in mind that 
the rules which determine action of waves^ 
while simple enough in themselves, are at the 
very heart of all modern physics. Most 
engineering textbooks make no effort to 
explain the rules — they merely state that 
the rules are foUowed, 

One volume which does attempt to ex- 
plain them in detail (Fields and Waves in 
Modern Radio, by Ramo and Whinnery) 
makes generous use of matrix algebra and 
differential equations derived from Max- 
well's Equations to present the explanation. 

But we're not afraid to take a chance on 
oversimplifying a complex subject in the 
interests of getting the main part of the idea 
across; we may make a few minor errors 
along the way but in general the following 
explanation is how it works. 

And you won't find the slightest trace of 



mathematics in it, either, 

A word of warning is in order, however. 
While the main idea is presented accurately, 
don't get into any arguments with physicists 
and cite this material as your reference. It 
may not be all that accurate; in case of 
conflict, believe the physicist! 

If you're still with us, then, let's dive 
right into just how '*wave mechanics" and 
"quantum theory" describe the interaction 
of radiated energy and matter- 
While nobody yet knows exactly what a 
"wave" of radiated energy amounts to or 
just how it manages to get from here to 
there, a number of ideas and concepts (the 
big brains call the "models'*) have ^ been 
developed — and most of them seem to fit at 
least parts of the needs pretty accurately. 
One of these ideaSj which is the basis of 

quantum theory, is that a wave consists of 
minute packets of energy called "photons" 

and that the amount of energy per packet is 

related to the frequency of the wave. The 

higher the frequency, the more energy per 

packet. 

In this scheme of things, a Ught wave 
packs more punch than does a radio wave, 
and an X-ray has more punch than either. 

The effects which we observe in waves, 
such as those of reflection^ refraction, diffu- 
sion, or scattering, occur only at the bound- 
aries where the wave moves from one sub- 
stance to another. So long as a wave is 
travelling in a single medium, whether that 
medium is air, a sheet of plastic, gl'iss, or the 
unknown substance today^s scientists call 
merely "space'' and the learned men of an 
earlier era knew as the "aether", it can 
produce no observable effect! 

IT 

At the boundary which separates one 
medium from another^ though, one major 
effect occurs, Tliis effect shows up as two 
distinct phenomena — and it's only because 
of them that we can teU that waves exist. 

The effect which occurs is an interaction 
between the wave's energy and the particles 
which make up the medium; normally these 
particles are atoms, but sometimes they are 
molecules and in a very special case they 
include electrons as welL 

The particular type of interaction which 
occurs depends upon the relationship be- 
tween the frequency of the wave and the 
self^resonant frequency of the particles in- 
volved. Each of the particles of atomic or 
molecular size does have a self-resonant 
frequency, and it's most convenient to think 
of them as being tiny tank circuits exposed 



102 



73 MAGAZINE 



to an excitation from the incomiDg wave. 

If the incoming wave is at a frequency far 
below that of the particle's resonance, the 
particle wiU vibrate werkly in phase with the 
incoming wave. 

If the incoming wave is at a frequency far 
above that of the particle's resonance, the 
particle will stiH vibrate weakly at the 
frequency of the incoming wave, but its 
vibration wiQ be 180° out of phase with the 
incoming excitation. 

If the incoming wave's frequency matches 
that at which the particle is resonant, the 
particle will vibrate strongly, 90*^ out of 
phase with the incoming wave. 

In most materials the particle resonances 
are at frequencies higher than that of visible 
light; a few substances have resonances as 
low as the infrared region, but almost none 
have resonance in the common rf range. 

For this reason, for most rf energy and 
almost aU materials the first case will hold 
true. Each particle at the boundary of the 
material will vibrate weakly and in phase 
with the incoming wave. 

There's a very special exception which we 
win meet a little later, in which both 
in-phase and out-of-phase vibrations occur. 
Before we look at that, though, let's stay 
with the first case and see what happens 
most of the time. 

Now as it happens, a vibrating particle 
will itself emit new radiation just because it*s 
vibrating. It's the same basic idea as that of 
the tuning fork, which you hit to make 
vibrate, and which then emits an audio wave 
because it is vibrating. 

This means that when an r/wave hits the 
surface of any substance, each particle at the 
surface of that substance wiQ re-radiate new 
waves which are in phase with the original 

rf. 

Each of these new waves wiU, in turn, hit 
adjacent atoms or particles within the mate- 
rial and cause additional vibrations and more 
re-radiation* 

If the particles are scattered about the 
substance more or less at random, as they 
are for instance in a gas, the total effect of 
all this secondary vibration wiQ be a "scat- 
tering** or "diffusion" of the original wave. 
The higher-frequency waves in the original 
energy (if a mixture of frequencies were 
present at the start) will predominate in the 
scattered new radiation, because they had 
more energy per photon to begin with. 

We see such an effect any time we look at 
a blue sky. The blue skyUght is the scattered 



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re-radiation produced by the molecules of 
the air when they aie hit by sunlight; the red 
of the sunlight is dissipated in the scattering 
process. 

If the particles are held in a reasonably 
rigid structure, though, as they are in most 
soHds, the effect of the new radiations is 
rather different. 

All of the individual re-radiations from 
the individual particles tend to cancel each 
other out, because the particles are regularly 
spaced. The only re-radiations that are not at 
least partially cancelled by this effect are 
those which happen to add up in "coherent 
phase" travelling in just one direction inside 
the material, and those from the surface 
layers of particles which have no other 
particles above them to produce cancelling 
re-radiation. 

The new wave inside the substance is 
known as the "refracted** wave. It may move 
at a different speed than did the original, 
and in a different direction as well, depend- 
ing entirely upon just how the particles of 
the substance are arranged in their rigid 
structure. 

The particles at the surface (a layer about 
half a wavelength deep) are producing re- 
radiation in all directions. These re-radi- 
ations all interfere with each other, just as 
do the cancelling ones inside the substance, 
but just what happens when they interfere 
depends upon the structure at the surface. 

If the surface of the material is smooth 
(using the wavelength of the incoming radi- 
ation as the yardstick to determine smooth- 
ness; anything with irregularities no more 
than 1/10 wavelength apart is considered 
"smooth"), then the radiations from the 
particles at the surface wiU interfere with 
each other just as do those inside the 
material to produce a single wave travelling 
in a single direction. 

The interference is normally such that the 
new wave from the surface particles — 
known as the "reflected** wave — leaves the 
surface at the same angle with which the 
original wave arrived, but in the opposite 
direction. This is the classic law of optical 
reflection as shown in Fig. 1. 

If the surface is rough (irregularities more 
than I/IO wavelength apart), then the re- 
flected waves from each surface particle will 
not add up to a single wave since each will 
have travelled a different distance at any 
given point away from the surface. Reflec- 
tion still occurs, but it is diffuse rather than 
sharp. A white cloud offers an optical 





-TTTTTTT? 

REntACTED^ •- 



// y J 7 y y y / / 



Fig, 1 — Classic optical example of reflection 
and refraction shovws that reflected ray always 
leaves surface at same angle it arrives. Refracted 
ray changes direction at boundary. If refracted 
ray passes through another boundary, as shown 
here, its direction changes again; if two bound- 
aries are parallel to each other final ray will be 
parallel to original ray (dotted) but offset from 
its path. If boundaries are not parallel, as in a 
lens, rays may be either spread apart or 
focussed to a point. Same effects are present in 
radio waves but because wavelength is much 
larger the effects show up somewhat differ- 
ently. 



example of this. So, for that matter^ does 
the white surface of the paper on this page; 
the paper particles are much larger than the 
wavelength of Mght, and so the light falling 
on the page is reflected diffusely. Where the 
ink is heavy, it forms a coating with a 
surface structure smaller than 1/10 wave- 
length of hght, and so appears glossy with 
sharp reflections. 

Since both light and rf waves are the same 
type of electromagnetic radiation, differing 
only in frequency, rf acts just the same 
way light does. The apparent differences are 
due to the vast difference in frequency; a 
structure which is quite smooth to an rf 
wave may consist of such widely scattered 
particles that it appears totally transparent 
to light, A screen-wire reflector is a good 
example of what we mean here. Another 
example is the ionosphere, although its rela- 
tive smoothness differs for rf of different 




Because of this, when a radio wave hits 
almost anything both reflection and refrac- 
tion wUl occur. The reflection is the basis for 
radar, and the refraction makes skip propa- 
gation possible (as well as possibly providing 
the mechanism for radio to exist in the first 
place^ if you consider the "radiated" wave as 
being refracted through space). 

But before we go any further we must 
examine the very special case of materials 
which are electrical conductors, because 
they behave rather differently than the 
ordinary solid substances we have been 
examining, 
an insulator lies in the atomic makeup of the 



104 



73 MAGAZINE 



r 



material A conductor contains numbers of 
"free" electrons which are bound only 
loosely to their parent atoms and which are 
free to wander about the interior of the 
material under the influence of electric 
forces. A perfect insulator has no such 
electrons, and actual insulators have very 
few. 

The free electrons in a conductor provide 
the means by which an electric current is 
conducted, and also make a large difference 
in the action of the material when a wave 
hits it, because both the free electrons and 
the particles which make up the substance's 
structure at the atomic level vibrate. 

The particles vibrate weakly, in phase 
with the incoming wave, just as do those of 
insulators. The free electrons, on the other 
hand^ vibrate out of phase with the incoming 
wave by 180 , also weakly. 

The vibrations of the free electrons cancel 
out the vibrations of the particles, and make 
it impossible for the wave to penetrate the 
boundary of the substance. Refraction can- 
not occur, because the energy can*t get 
inside the material 

But the energy is stiU striking the surface, 
and the surface layer of particles is stiU 
vibrating. This permits reflection to occur. 
Whafs more, the law of conservation of 
energy requires that all energy going into 
something must come out again — and since 
no refraction can occur, all the energy taken 
from the incoming wave is reflected from 
the surface. 

Thus a conducting surface will reflect aU 
the rf which hits it, while an insulating 
surface will reflect only a part and will 
refract the rest through itself. 

Conducting reflectors play a large part in 
antenna design; the principles of reflection 
(particularly that of re-radiation) are also 
important in understanding action of para- 
sitic antennas. 

The effect normally known as "signal 
reflection*', though, is more often actually 
due to refraction than to reflection. Such 
things as skip transmission, meteor trail 
communication, and aurora-reflected signals 
are actually effects of refraction. Moon- 
bounce and scatter work, however, are true 
reflection phenomena. 

The reason why refraction can masquer- 
ade as reflection is illustrated in Fig. 2, 
which shows refraction at work in one of the 
ionized layers responsible for skip trans- 
mission. 

When a wave is refracted, both its speed 



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and direction usually undergo change* Speed 
may either increase or decrease; the change 
of direction usually depends upon what 
happens to the speed. 

If the refracting medium has character- 
istics which change gradually within the 
material, the speed and direction of the 
refracted wave wiU also change gradually as 
the wave proceeds in the materiaL 

The ionized layer is such a medium; its 
makeup changes — both from minute to 
minute (and other periodic changes) and at 
various points within the layer at the same 
time. 

Thus a wave transmitted from the earth 
will be bent or refracted only slightly as it 
enters the ionized layer, but the deeper it 
penetrates into the layer the more its direc- 
tion is changed. When the original direction 
has been changed enough to turn it around a 
corner, the wave is moving out of the 
material rather than in, and then the change 
in direction becomes less the farther it 
travels. 

Eventually the wave wUl come back out 
of the layer, provided tiiat the refraction 
doesn't just happen to trap it completely 
within the layer and bend it only enough to 
keep it trapped. Even if this should happen 
at some spot, there are enough irregularities 
in the layers that the energy would escape 
elswhere — and such an action may be at 
least partially responsible for some types of 
fading. 

As Fig. 2 shows, when the wave emerges 
from the layer there is no way at all you can 




Fig. 2 — Refraction of radio wave in ionosphere 
is cause of apparent "reflection" of skip signals 
as shown here. Since ionization level changes 
graduallv within an ionized layer, angle of 
refraction is continually changing. This bends 
wave back in new direction, making it appear to 
have been reflected from a surface at somewhat 
greater height (dashed line). Wave reaching 
layer at shallow angle (dotted) does not pene- 
trate so deeply as one hitting at sharp angle 
(solidl; therefore it is bent less and so returns to 
earth at greater range than difference of angles 
alone would indicate. 

detennine that it wasn't simply reflected 
from a sharp surface at a somewhat greater 



height. This fictional reflecting surface's 
height is what is referred to as the "virtual 
height" of the skip layers. 

The reason we know it works by refrac- 
tion rather than reflection is that the virtual 
height of a layer appears to change with the 
angle at which energy hits it. The shallower 
the angle, the lower the virtual height. You 
can see from the dotted-line example in Fig. 
2 that this would be expected with refrac- 
tion, but not with reflection. 

This mechanism in the ionisphere indi- 
cates that the angle at which the signal will 
be "reflected" depends critically upon the 
angle at which the signal arrives, and also 
upon the condition of the ionized layer at 
that particular time. High-frequency signals 
packing more punch per photon, bore right 
on througli much more readily than do those 
of lower frequency — so that as you keep 
going up in frequency, you find a point at 
which the signal simply doesn't come back 
down. Instead, it bores on out headed 
toward outer space. 

The angle at which the signal hits the 
layer depends, in turn, upon the actual angle 
at which the wave leaves the transmitting 
antenna. This depends upon the antenna 
design, its height above electrical ground, 
and the nature of the ground surface within 
several wavelengths of the antenna site. The 
lower the angle at which the signal leaves, 
the more sh allows will be the angle at which 
it hits the refracting layer^ and the greater 
will be the distance covered before it returns 
to earth. 

Any substance which is capable of refrac- 
ting the wave can cause **reflection" by 
refraction in this same manner. In addition 
to the horizontal ionized layers which make 
up the ionisphere, rf signals are frequently 
"reflected" from the aurora boreahs and 
from the trails of ionization left beliind by 
meteors- At VHF, similar effects are caused 
at the boundary between different layers of 
air in the atmosphere. 

How Does Reflection Affect the Signal? 
True reflection has virtually no effect upon 
the signal, except that its phase changes 
180 during the process of reflection, '*Re- 
flection^' by means of the refraction effect, 
though, can affect a signal in many ways. 

Reflection of VHF signals from the shim- 
mering veils of ionization which are known 
to science as the aurora and to the general 
public as '*the Northern lights" offers several 
examples of such effects. 

The aurora is a rapidly moving affair. Its 



106 



73 MAGAZINE 



exaci cause and composition is still not 
accurately known, but it is believed to be 
especially intense ionization of the upper 
atnmsphere under influence of solar radia- 
tion trapped by the earth's magnetic field. It 
is visible as curtains, colunins, and some- 
times liorizontal sheets, and moves in both 
the horizontal and vertical planes at rela- 
tively high speeds. 

Often, the aurora appears to shimmer 
with a to-and-fro motion. 

Any radiation reflected (that is, refracted 
back toward the source) from these clouds 
has a frequency sliift imposed upon it by the 
motion of the clouds, by Doppler effect. 

This frequency shift is, effectively, FM of 
the original signal, in which the modulating 
signal is the oscillating movement of the 
aurora itself. 

The frequency of the aurora^s oscillation 
is often so great that the resulting FM 
completely wipes out any intelligibility of 
audio upon the signal and makes a CW 
signal appear to occupy a wide band rather 
than the normal near-zero bandwidth. 

If aurora -re fleeted signals are received by 
the normal CW method, using a product 
detector or BFO, the FM causes the received 
signal to appear to warble. But since the 
reflection is coming to the receiver from a 
wide source — the entire aurora cloud — and 
part of it is moving toward the receiver while 
other parts are moving away, it isn*t just a 



4BOVE CRtTtCAL ANGLE 



J.'h,'. I'v'.-.vui 




-—RANGE OF SKiPAftJGLES 



Fig. 3 — Various effects of transmission angte 
(angle at which wave leaves transmitter) are 
shown in this sketch. The longest skip distance 
is achieved by the wave with the lowest 
transmission angle, and the shortest by that 
with a moderately high angle. As angle in- 
creases, wave is held in ionized layer longer and 
skip distance increases again. Such waves are 
called "Pedersen waves" and may interfere with 
lower waves from same transmitter as shown. 
Still greater angles permit wave to pass on 
through ionized layers if ionization is suffi- 
ciently weak, 

single warbling note. Instead, it's a mixture 
of frequencies covering the entire audio 
range. The resulting sound has been com- 
pared to the whine of a buzz saw going 
through a pine knot , . . 




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107 



Just to complicate things, most aurora- 
reflected signals are very weak; very little of 
the original signal is reflected to any one 
receiver. The signal*! o-noise ratio is often as 
low as Eero db. 

Somewhat the same situation prevails 
when the trail left by a falling meteor 
provides the refracting ionization* In this 
case, though, the warble is absent. Any 
Doppler shift is usually constant. Signal 
levels, however, are much lower because the 
refracting volume is much lower. 

Scatter techniques depend more upon 
true reflection, of the same type that makes 
an oncoming automobile's headlights visible 
over the rim of a hill on a foggy niglit. The 
original signal is reflected in all directions by 
tiny discontinuities in the atmosphere (tropo 
scatter) and ionosphere {ionospheric scatter). 
Scatter transmission provides the most 
rehable and consistent form of long-distance 
rf communication, but requires power levels 
greater than those allowed the ham by law 
to attain reasonable distances with high 
reliabOity. At amateur power levels, dis- 
tances are so short that most scatter signals 
are thought to be '^ground wave" instead. 

All of these effects are present with all 
radio frequencies, but their effectiveness 
varies with frequency. At moderate fre- 
quencies (15 meters and below) they are 
usually overpowered by ''normal" skip trans- 
mission. In the VHF range they are most 
observable, and many VHF operators spe- 
cialized in using one or more of these 
techniques. As the frequency goes on up, the 
amount of refraction becomes too small to 
return a usable signal level and the effect 
again appears to disappear. 

How Is A Signal Radiated? The subject of 

just how an rf signal can be propagated is a 

'most profound one, and virtually aU the first 

installment of our previous Advanced class 

study course (March, 1968, issue) was de- 
voted to it, 

A few minor modifications to the propa- 
gation model we put together in answer to 
our question "'How Does Signal Reflection 
Occur?*' can, however, offer some additional 
insight into the subject. 

As we explored reflection and refraction, 
we discovered that a conductor cannot 
refract a wave but must reflect it. At that 
point, we declared that the energy had no 
place else to go and so all the incident wave 
went back out as a reflection. 

If, however, the conductor happens to be 
serving as an antenna, that statement was 



NOT RETURNED 




XMTR 



Fig. 4 — Both single and multiple-hop propaga* 
tion are shown here. Wave launched at original 
angle for shortest skip range hits earth at 
moderately steep angle and is reflected back 
toward ionosphere. There it is refracted again 
and comes back down at double the original 
distance. "Skip distance" is distance from 
transmitter to the minimum 1-hop point; this 
region is sometimes called the "dead zone". 
Waves launched at higher angles fail to return 
(except for Pedersen waves, see Fig, 3). Those 
launched at intermediate angles fall between 
minimum and maximum 1-hop ranges. 

not fully correct. The energy does have some 
place else to go — down the feedline. 

In the case of a transmitting antenna, 
energy is coming up the feedline instead. In 
either case, the system is no longer in perfect 
balance. 

When the frequency of the wave which is 
exciting the antenna is such that a standing 
wave can develop on the antenna structure 
itself, it does so. This standing wave can be 
thought of as the re-radiated wave from all 
the surface particles. However, since the 
standing wave maintains a perfect phase 
relationship with the radiated energy, it will 
couple with the radiation field and permit a 
much more efficient transfer of the energy 
itself. 

What's more, the fields of the standing 
wave will induce a current inside the con- 
ductor — where the radiated wave itself 
cannot get because of reflection at the 
surface. This action is what moves the 
energy through the tol ally-re flee ting bound- 
ary of the conductor. 

If we're trying to radiate a signal rather 
than receive one, we begin by pumping 
energy into the antenna conductor at a 
frequency at which the antenna has eiectricl 
resonance. This produces a standing wave 
upon the antenna, and tins standing wave is 
accompanied by a magnetic field which Is 
directly' associated with current flow in the 
conductor* 

The variation in the magnetic field is 
accompanied by a variation in the electric 
field estabhshed between the ends of the 
antenna conductor, and the phase relation- 
ships between the magnetic and electric 
fields which result are such that the *'wave" 
which they define is a travelling wave rather 
than a standing wave. 



108 



73 MAGAZINE 



A travelling wave is, by defijutionj one 
which is being radiated through some medi- 
um — usually "space". A standing wave, on 
the other hand, is confined to a physical 
structure such as an antenna- 
While most antennas radiate by means of 
a standing wave created upon their structure^ 
this is not an absolute requirement. Any 
resonant antenna has a standing wave, and so 
do such "non-resonant" antenna types as the 
long wire. 

The terminated V, the rhombic, and the 
Beverage antenna designs, however, all make 
use of travelling waves without requiring a 
standing wave as well. 

Travelling- wave antennas are inherently 
less efficient in the transfer of energy for a 
given amount of wire; the absence of the 
standing wave to help couple energy from 
inside the conductor to the outside of it 
must be paid for in a much larger structure. 
Travelling- wave antennas are almost invar* 
iably several wavelengths long, while the 
most common standing- wave antenna is the 
half- wave dipole, and the quarter- wave whip 
is no rarity either. 

The difference is brought about largely 
by the difference in current distribution in a 
travelling-wave antenna as compared to a 
standing- wave antenna. Fig. 5 A shows the 
familiar standing wave of current upon a 
resonant antenna; Fig, 5B shows the current 
distribution on a travelling- wave antenna. 

The difference is marked; in the resonant 
antenna, current is highest near the center 
and drops to virtually zero at each end, 
whOe in the travelling- wave antenna the 
current is essentially constant throughout 
the conductor, dropping only because of 
radiated energy. 

Those portions of the conductor which 
carry the greatest current are simultaneously 
surrounded by the strongest magnetic field 
since the magnetic field and the current are 
closely associated. 

As this magnetic field couples to its 
surroundings, each tiny portion of the 
antenna acts as if it were a separate source of 
radiation. 

With the constant current in the travel- 
ling-wave antenna, all these separate sources 
are radiating in essentially the same phase 
(the only phase differences are those intro- 
duced by the physical length of the con- 
ductor) and at essentially the same strength. 
The result is an interference pattern which 
causes most of the individual fields to cancel 
each other out just as did the re-radiation of 



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Fig. 5 — Difference In current distribution 
between resonant antenna lA) and terminated 
or travel ling- wave antenna (B) creates dif- 
ferences In radiation patterns. On resonant 
antenna, current goes in different directions at 
different points to create standing wave. On 
ternr>inated antenna, current flow is all one-way, 
from feed point to termination. Both antennas 
are shown as being "current-fed" at maximum 
current points. 

individual particles in refraction. Those 
which add up instead of cancelling become 
travelling waves leaving the antenna. 

In the resonant antenna^ the separate 
portions of the conductor axe not necessarily 
in phase with each other because the total 
reflection at the ends of the antenna intro- 
duces a 180 phase change, and they most 
certainly are not of equal strength as radi- 
ators since the current is not constant 
Mutual interference still operates to cancel 
out most of the fields and leave a radiating 
travelling wave - but the pattern is 
different- 

The most noticeable difference is that the 
travelling- wave antenna is unidirectional 
wlule the standing- wave antenna is not This 
is because the current in the travelling-wave 
antenna is flowing onJy one way, while in 
the standing'Wave antenna current is flowing 
in both directions (out and back) at the 
same time to create the standing wave. 

Fig. 6 compares the directional patterns 
for a terminated long- wire antenna (a travel- 
ling-wave type) and for a resonant long-wire 
of the same length, 

A key point to keep in mind concerning 
signal radiation is that each individual small 
part of any radiating structure, such as an 
antenna, radiates with equal strength in all 
directions. Its radiation pattern is essentially 
a perfect sphere. 

However, any radiating conductor which 
has any length at all must be composed of 
many such small parts, and each of them is 
radiating in slightly different phase from all 



the rest since the exciting energy takes at 
least a little time to get from one to another, 
and phasing is time delay. 

The result is that any possible (as 
opposed to theoretical) antenna must have 
some type of radiation pattern, which is the 
result of the interference pattern created by 
the individual spherical patterns of its indi- 
vidual parts. That's why we looked at 
refraction and reflection first; the exact 
same principle is involved in the creation of 
the radiation pattern for any antenna, and as 
we shall discover shortly is also involved in 
our efforts to concentrate a signal in a 
desired direction. 




Fig. 6 — A— Radiation pattern of terminated 
antenna four wavelengths long is unidirectional 

in general direction of the wire, but has a null 
directly off the wire's end. The pattern's main 
lobes make 26° angle with wire. Pattern is 
symmetrical in three dimensions: consider this a 
cross-section view of it looking down from top- 




Fig, 6 -- B — Resonant antenna of same 4-wave- 
length length has this type of pattern; it's like 
the terminated antenna's pattern with a mirror 
image superimposed on it. Result has main 
lobes in both directions, still with 26^ angle and 
symmetrical shape. Bidirectional current ftow 
{Fig. 5) is directly responsible for this bidirec- 
tional pattern. 

How Can a Signal Be Concentrated? The 
'isotropic" antenna^ which doesn*t exist in 
practice but is the basis of antenna theory, 
radiates any power applied to it with equal 
strength in all directions. Its radiation pat- 
tern is a perfect sphere. 



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As we just saw, any possible physical 
antenna must be made up of several dif- 
ferent atoms and so cannot be a perfect 
isotropic antenna — but even if we could get 
one, nobody would want it, rf power is too 
difficult to generate to waste by beaming as 
much signal straight up into space and 
straight back down into the ground as we 
send in the desired directions! 

Any practical antenna performs at least 
some concentration of its signal, then, by 
putting it aU into its radiation pattern. What 
we're really concerned with here is how we 
can concentrate the signal even more. It 
would be nice^ for instance, to be able to put 
all our power in just the direction we wanted 
to transmit, without wasting any of it in 
undesiied directions. 

Such antenna designs exist, of course, and 
are known by the general name of "beam 
antennas*' since their purpose is to concen- 
trate as much of their power as possible into 
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At least four major types of beam 
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systems, and (4) travelling- wave antennas. 

Driven arrays include broadside arrays, 
endfire arrays, and combinations of the two. 
The Lazy H, ZL Special^ 8JK beam, and 
Franlkin Collinear array are examples of 
driven arrays, as are most directive BC- 
station instaUations. 

Almost all parasitic arrays are of the 
endfire type; the most common such design 
is the Yagi anteima. 

Reflective systems are used primarily in 
the UHF and higher-frequency regions, and 
include the **big dishes" and the corner 
reflector. 

Travelling-wave antennas include the 
terminated V, the rhombic, and their varia- 
tions; these are most usually used only at 
low frequencies where the other types of 
beams are not practical. One type of travel* 
ling- wave anterma in wide commercial use at 
high frequencies is the heUcal beam. 

Any single beam antenna installation may 
mix or match these types. Especially popular 
among VHF workers is a combination of 
driven and parasitic arrays in which several 
separate parasitic arrays are driven at the 
same time to form a driven array of parasitic 
arrays. Fig. 7 shows the idea. At UHF, a 



' 



"^^ ■■ 




ni 



^ 



corner reflector is sometimes incorporated 
into a parasitic array to increase the beam 
concentration and reduce unwanted back- 
lobes. 

Since most beam antennas in ham use are 
either driven arrays, parasitic arrays, or 
combinations of the two types such as that 
shown in Fig, 7, we'll concentrate on only 
these two types for now. 




Fig. 7 — Quad Yagi antenna installation popular 
with serious VHP enthusiasts is typical example 
of an arrav of arrays. Each of the four Yagis is 
itself a parasitic array, and the four are arranged 
and fed as a tvvo*by-two broadside driven array. 
Result is highly directional pattern and maxi- 
mum gain; as much as 18 db power gain can be 
achieved in practical amount of space with 
careful design and adjustment. 



The driven array consists of a number of 
individual antennas arranged in some regular 
pattern, all of which are driven at the same 
time from the same source. It*s exactly the 
same principle as the radiation from separate 
atoms in refraction, except that it's at a 
much larger scale. 

Fig. 8 shows the e":sential portions of any 
driven array; each individual antenna is 
shown here only as a dot rather than as a 
wire, because it*s easiest to see what's 
happening if we think of each individual 
antenna as an "isotropic"" one for the 
moment- 

If each of the individual antennas is fed 
with current of exactly the same phase, then 
the array is a "broadside array" because it 
will concentrate the pattern to be strongest 
in the directions broadside to the line of the 
antennas. That is, the pattern shown in solid 
lines wUl result. 

This is caused by interference between 
the patterns of the individual antennas. Only 
at point P (and other points along the line 
between P and the center of the array) will a 
receiver get equal amounts of in -phase 
energy from all the individual radiators. At 



other angles, the waves from one antenna 

must travel further (and so take longer en 
route) than those from another, and so will 
arrive out of phase > This causes a partial 
cancellation. The pattern is the result of all 
these partial cancellation effects. 

If, however, the antermas are fed differ- 
ently, the pattern will change. For instance^ 
if the feedline is connected directly to the 
leftmost antenna and goes to the adjacent 
one through an additional length of cable 
which introduces a phase delay, and so forth 
down the line, and if that phase delay is 
chosen just right so that the energy feeding 
each array is in phase with the energy 
arriving from its neighbor to the left, then 
the only point at which all antennas con- 
tribute equally is that marked Q. The result- 
ing radiation pattern is shown in dotted lines 
in Fig. 8, and the array is now an *' end fire 



A 




aRCAOSLDE 



EhTjFlRE 






Fig. 8 — Basic patterns of driven arrays are 
broadside and endfire as shown here. For 
simplicity, each element of this array is shown 
as an isotropic {point-source) radiator and all 
minor lobes have been omitted. Both patterns 
repeat themselves in opposite direction; that is, 
they are bidirectional. Difference in direction 
between broadside and endfire patterns is due 
to feedline phasing within array; main lobes can 
be tilted to any in-between angle by proper 
phasing but this is not usually done with ham 
antennas. 



array" since it fires its strongest beam off 
the end of the line of antennas. The only 
change necessary to obtain this 90-degree 
change in direction was to change the 
phasing of the feed lines. 

By appropriate choice of phase relation- 
ships between the various antennas in a 
driven array, the beam can be tilted to any 
point between the broadside position and 
the endfire pattern. This is done in BC- 
station design, but in ham work it's much 
easier to simply rota e the array. 

If, instead of the imaginary isotropic 
antennas we used in Fig. 8, the individual 
elements of the array are dipoles (as they 



4 4 



1*^ nil An A ■?) MC 




usually are) then the radiation pattern of the 
dipole gets into the act. Broadside arrays 
made up of dipoles are usually set up either 
parallel to each other, )r end to end, as in 
the *'colinear" antenna, Endfire arrays of 
dipoles on the other hand usually have the 
antenna conductors arranged at right angles 
to the line of radiation, like the Yagi 
parasitic array (which has an endfire radia- 
tion pattern). 

A parasitic array is essentially a driven 
array in which only one of the antennas is 
actually driven, and the rest pick up their 
energy by radiation from that one. Most 
parasitic arrays are endfire designs, since it^s 
simple to get the necessary coupling and 
phase relationsliips from parallel dipoles. 

The phase of the energy actually radiated 
from an antenna depends, in part, upon the 
relationship of the exciting energy's fre- 
quency to the frequency at which the 
antenna is self-resonant. The phasing adjust- 
ment which, in the endfire driven array, was 
made by adjusting feed line length, is made in 
a parasi*:ic array by tuning the parastic (non- 
driven) elements to frequencies slightly dif- 
ferent from tliat at which the antenna is to 
operate. 

If an element is tuned to a frequency 
slightly lower than that at which operation is 
desired, the phase of its reflected or re-radi- 
ated energy will be such as to cut down the 

radiation pattern in its direction, and build it 
up in the opposite direction. Such an ele- 
ment is called a "reflector". 

If an element is tuned to a frequency 
slightly higher than that at which the beam 
is to operate, it will build up the radiation 
pattern in its direction and cut it down in 
the opposite direction. Such an element, 
since it directs the pattern in its own 
direction, is called a "director*'. 

The spacing between the driven element 
and the parasitic elements is just as critical, 
in a parasitic array, as is the tuning of the 
parasitic elements, since the array's per- 
formance is determined, by relative phase 
over the entir6 structure. Distance deter- 
mines phasing also. For any specific tuning 
of a parasitic element, there is a critical 
distance as welL 

Before the principles of the parasitic 
array were understood as well as they now 
are, this led to many conflicting rules for 
design of parasitic beams and their tuning. 
About 10 years ago, howeven it was dis- 
covered that the critical factor actually is the 
combination of tuning and spacing. It is now 



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1 



MAY 1969 



113 



pp 




known that almost any spacing (within 
reason) can be used, or alternatively almost 
any tuning of element lengths. Once a 
spacing is chosen, then the tuning of the 
elements must be matched to it; if element 
tuning is chosen first, then the spacing must 
be adjusted to obtain maximum perform- 
ance. 

In comparison to the other three types of 
beam antennas, parasitic arrays offer the 
highest performance per unit size. On paper 
at least, you can get any desired gain from a 
physically small parasitic array if you just 
use enough elements and tune and space 
them properly. In practice, the gain really is 
limited — but you can get a 10-time increase 
in effective radiated power from an antenna 
only a half wavelength wide and a wave- 
length long, which is much more than any of 
the other types of beam can provide. For 
this reason many engineers caU such designs 
*'super-gain" antennas. 




Fig, 9 — Buildup of radiation pattern for termi- 
nated V antenna with each leg 4 wavelengths 
long is shown. Each leg of V by itself has 
pattern of terminated long-wire (Fig. 6); legs 
are placed at proper angle to make main lobes 
coincide in one direction, and cancel out to at 
least some degree in atl others. 

The travelling-wave antenna, such as the 
rhombic or the terminated V, gets its gain by 
a cancellation effect also. As Fig. 6 showed, 
a travelling-wave antenna is inherently unidi- 
rectional — but puts its power into a cone 
rather than a beam. If two such antennas are 
erected side by side to form a V as shown in 
Fig. 9, their patterns can be made to cancel 
each other out in most directions while they 
add together in just one and form a single 
beam of radiation. This is the terminated V. 
If the terminations at the wide end of the V 
are removed and another pair of antennas is 
put in their place, with terminations at the 
narrow end (Fig. 10), you have the rhombic. 
Gain of such an antenna is moderately high, 




BOOST 



CANCEL 




Fig. 10 — Simplified buildup of pattern for 
rhombic antenna is similar to that for termi- 
nated V; lobes aimed in same direction boost 
each other and all the rest cancel. Cancellation 
is more complete in rhombic* 

but is nowhere near that to be expected 
from either a driven array or a parasitic of 
simUar size - because each leg of the 
rhombic needs to be at least four wave- 
lengths long to get the directive effect. 

You can also get some directivity from an 
u/3 terminated V. This is essentially two 
long-wires side by side. The cancellation 
effect still works to take out part of each 
long-wire's pattern, but the resulting beam is 
bidirectional with its major lobe splitting the 
V angle as shown in Fig. 11. 



BOOST 



V 




Vboost 



Ftg. 11 — In unterminated V antenna, lobes in 
both directions boost each other but side lobes 
cancel out. Result is bidirectional beam, similar 
to that of broadside or endfire pattern from 
driven array. 



The resulting pattern is similar to that 
you get from a simple driven array (Fig. 8). 
A parasitic array, on the other hand, concen- 
trates its power essentially in a single di- 
rection^ as does the terminated V or the 
rhombic. 

The subject of antennas and how they 
work is one of the most important in ham 
radio, because nowhere else can you get such 
an improvement in your station's perform- 
ance for a comparable amount of effort. 
We'll be going into it more in our next few 
installments, but even then we will not be 
able to cover it completely — the subject is 
just too large- 

A number of books are available at 
various levels of technical knowledge. The 
traditional authority on the subject is "An- 
tennas", by John Kraus, W8JK, inventor of 
the 8JK beam, the comer reflector, and the 
helical beam, Terman's **Electronic and 



114 



73 MAGAZINE 



Radio Engineering" contains much valuable 
data at a slightly less exotic level, being 
intended as an undergraduate text for engi- 
neering students at the college junior/senior 
level, '* Fields and Waves in Modern Radio" 
by Ramo and Whinnery handles the basic 
principles of radiation excellently but re- 
quires at least an acquaintance with higher 
math (matrix algebra and partial differential 
equations) to read comfortably, Jasik*s "An- 
tenna Engineering Handbook" is intended 
for the antenna design engineer but avoids 
much of the deeper theory and concentrates 
on practical appMcations instead. Any or all 
of these are recommended for additional 
study, if you're really interested in adding to 
your knowledge of how and why antennas 
work as they do. 

Next Month. We'll continue examining 
antennas, looking at such factors as har- 
monic rejection and feediine matching. 



RENEWAL CODE 

Th© two numbers under your call on the ad- 
dress label are the explrafion code* We have 
tried to make it simple. The first number is the 
month that we send y^^ ^^^ 1^^^ copy on your 
subscription and the second number is the year, 
78 would be July I966| for exarnple. 

73 MAGAZINE 



Those Army Set Screws! 

One of the big problems faced by every 
would be user of the Command Transmitters 
is the frustrating task of loosening those spe- 
cial set screws on the knobs and shafts of this 
series. UsuaUy one ends by using brute force 
and damaging the part, or just laying the 
equipment aside. 

One of the regular screwdriver blades in 
the SC-5 Screwdriver set which can be pur- 
chased from the radio houses, or any good 
screwdriver with a very small blade will just 
fit into this set screw and with a stout twist 
will loosen any of them very quickly- If 
this screwdriver set is not available, grind 
any stout screwdriver down to about i/16th 
of an inch, and they will fit into these set 
screws cross-wise. 

The knobs and shafts of this Command 
series suddenly become very valuable. 

Irvin Kanode, WA9CKP 



"THE COMPLETE HAM STORE" 
WHERE YOUR DOLLAR BUYS THE MOST 

All leading lines of amateur gear: 
We give best trade-in allowance 
for your gear on new equipment: 
Call us for the best deaf: 

WE PAY CASH FOR HAM & CB RADIOS 
CALL OR WRfTE 

BOB'S AMATEUR ELECTRONICS 

927 N.W. Ist. St.. OKLA. CITY, OKLA. 73106 

Phone 405.CE-S-6387 






ANTENNAS • TOWERS • ROTORS 
NEW • USED • SURPLUS 

Hy-Gain Mosley CDR Newtronics 

TristdO Kreco 
Mylar rope insufators Coax baluns 
One-piece fo Complete Antenna 

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Also Deal in Surplus — 

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SERVICE AND FRIENDLINESS 

To Radio Amateurs For 32 Years 

WE MUST BE DOING SOMETHING RIGHT. 




PHONE 

518-842 

8350 



USED EQUIPMENT 

Clegg 22'er Factory overhauled— $177 



Ham marl una 

HQ-170-$190 
HQ-180C-$250 
*HX-50-$225 



Collins 

# 75A1-$120 
75A4-$425 
62S1-$600 
KWM-1-$229 

* Drake SW4 A-$250 

Globe King 500C was $310, now $289 
Hallicrafters SRI 60 + PI 50 DC— $250 
Hallicrafters HT-44 was $200, now $175 

a|k Johnson Valtant I + BW 5T00-$210 
National NCL-2000— $389 

SBE 34-$325 
Swan 350— $350 

Mark II Linear— $550 

TV-2, 14MCIF-$260 

*^Equfpment on const ffjimenL No trades of disc4>unt5. 
Prices may he ihcounie6 10% In lieu of trade, 

Just off Exit 27 on Thruway 

Distributors of all fnafor lines 

of amateur equipment. 

Its WEST MAIN, AMSTERDAM. N.V. 120T0 



MAY 1969 



115 



i 



IW 



1 




NEW BOOKS 



Electronics for Technicians 

Written by Abraham Marcus and published 
by Prentice-Hall, Electronics for Technicians 
is a sequel to Electricity for Technicians- It 
describes electronic phenomena in physical 
terms, rather than mathematical and is ex- 
tremely well-writteii- 

The book is divided into three sections. 
Section I deals with the electron tube. The 
various types of tubes are discussed in lang- 
uage which almost anyone with any electron- 
ic knowledge can easily understand- Section 
II discusses semiconductor theory and the 
various types of semiconductors are examin- 
ed. Section III deals with how tubes and 
semiconductors are used in various circuits 
including power suppUes, amplifiers, oscil- 
lators and various circuits used in the home^ 
in industry and communications- Mr, Marcus 
gives an overall view of the subject and liis 
book should serve as a basic foundation for 
further study in electronics. 

The book is divided into 20 chapters with- 
in the three categories, and each chapter is 
followed by a series of questions for the stu- 
dent to test his comprehension of the mater* 
iaL Following the 20 chapters is a series of 
apen dices showing pin identification for elec- 
tron tubes» lead identification for various 
transistors, and a complete section on elec- 
tronic symbols which is the most up-to-date 
I have seen so far. 

In an attractive cloth-botmd cover, Elec- 
tronics for Technicians sells for $9.95 and 
certainly contains all the study material need- 
ed for anyone interested in learning basic 
theory. 



RCA Manuals 

The RCA Solid-State Hobby Circuits Man- 
ual contains complete construction informa- 
tion on 35 circuits of general interest to ex- 
perimenters* Power supplies, oscillators, key- 



ers, preamplifiers, amplifiers, and numerous 
other items are covered in detail. This manual 
also contains sections on theory and practical 
application of most solid state devices^ and 
gives information on construction practices 
and trouble-shooting. 

The revised and expanded RCA Receiving 
Tube Manual contains up-to-date information 
on tube types and technology; detailed des- 
criptive data and application information for 
the complete line of home-entertainment 
types of receiving tubes for TV and Hi-Fi en- 
thusiasts. 

Seven other technical manuals are available 
from RCA. RCA Transistor Manual is a 544 
page book containing text, data, and typical 
circuits for the complete line of transistors, 
silicon rectifiers, and other semiconductor 
diodes. 

RCA Silicon Power Circuits Manual is a 
416 page book providing design information 
for a broad range of power circuits using sili- 
con transistors, rectifiers, and thyristors- 

RCA Linear Integrated Circuits (352 pgs,) 
contains basic principles of design and appli- 
cation information for linear integrated cir- 
cuits- 

RCA Silicon Controlled Rectifier Exper- 
imenter's Manualissi 136 page book contain- 
ing 24 interesting control circuits using semi- 
conductor devices available in kit form- 

RCA Transmitting Tubes is a 320 page 
book giving data on more than 180 RCA 
power tubes with plate input ratings up to 
4 KW. 

RCA Phototubes and Photocelh (192 pgs.) 
contains design information and data for 90 
photosensitive devices. 

RCA Tunnel Diodes is a 160 page book 
containing information for RCA tunneldiodes 
for switching and microwave applications. 

Prices range from S .65 to S5*75, For a 
complete brochure and prices write Commer- 
cial Engineering, RCA Electronics Compon- 
ents, Harrison, NJ* 07029. 

Motorola Semiconductor Handbook 

The Semiconductor Power Circuits Hand- 
book contains the latest information in power 
circuit design. Some 150 new circuits have 
been specifically designed for users of power 
transistors, thyristors, rectifiers and zener 
diodes. This 264 page manual includes many 
designs being published for the first time* It 
is divided into six chapters devoted to motor 
speed controls, inverters and converters, reg- 
ulators, statis switches, audio and servo amp- 
lifiers, and miscellaneous thyristor switch ap- 



116 



73 MAGAZINE 



lilications. Copies may be obtained by send- 
ing S2 to Motorola Inc., Box 20924, Phoenix, 
Arizona 85036- 

Hayden Books 

This one is a beauty. The Transistor and 

Diode Laboratory Course, by Harry E. Stock- 
man, clearly illustrates and develops the con- 
cept of transistor theory. This 117 page book 
is designed either for the classroom or for 
home study. The first half of the book is 
devoted to theory, providing a background in 
transistor technology- The remainder is ex- 
periments deahng with intricate transistor 
networks. Each chapter is followed by a 
question and answer session. For anyone who 
wants a more sophisticated approach to 
transistor theory and application, this book 
is a must. Available for $3.95 from May den 
Book Company, Inc., 116 West 14 Street, 
N. Y.. N. Y. 1001 L 

New Books From Sams 

Reference Data for Radio Engineers (Fifth 
Edition) 50% more information with a com- 
pletely new format. Catalog No. 20678, $20, 

Amateur Radio SSB Guide. Basic princi- 
ples, building and troubleshooting. Catalog 
No. 20629, $3.95. 

Learn Electronics Through Troubleshoot- 
ing. A basic, practical approach to learning 
the fundamentals of electronics. Catalog No. 
20651, S6.95. 

Novel Electronics Circuits. 77 new cir- 
cuits and devices to buOd. Catalog No. 20692, 

The Radio Amateur's FM Repeater Hand- 
book. A 288 page book by Ken Sessions. 
Catalog No, 65080, S6.95. 

73 Dipole and Long Wire Antennas, Cov- 
ers practically every type of wire antenna 
used by amateurs. Catalog No. 65071 , $4.50. 

Amateur Tests and Measurements, Tests 
and adjustments to transmitters, receivers, and 
antennas. Catalog No, 65072, S4.95. 

Hani A ntenna Construction Projects. (Sec- 
ond Edition) Modern versions of all classic 
antennas* Catalog No, 20654, $3.95. 

Handbook of Electronic Tables and Form- 
ulas. One book with all the charts, tables, 
symbols, and all you need. (Third Edition). 
Catalog No. 20648, S5.50. 

FET Principles, Experiments, and Projects. 
Breadboarding to teach FET operating char- 
acteristics. Catalog No, 20594, $4,95. 

Know Your Tube and Transistor Testers. 
Troubie-shooting and repairing various makes 
and models. Catalog No. 20630, $3.50 




I 



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No C.O.D. Include necessary postage. 



MAY 1969 



117 



Economy 



Ed Baker. W0EDO 
9937 Truman Road 

Independence, Missouri 



Chronometer 



How would you like to have an illuminat- 
ed station clock for less than S5.00? 

The unit described was built at a total 
cost of S3, 14 plus tax, but, with a well- 
stocked junk box, this figure could be reduced 
still further. 

The secret of such a bargam lies in the fact 
that most "electric'' automobile clocks are 
really mechanical clocks which are wound 
electrically every two tu five minutes. Since 
this winding is done by a pulse through an 
electro magnet, the clock doesn't care whe- 
ther this pulse is ac or dc, thus making it a 
simple matter to power the clock in the home 
station. 

These clocks are available from your local 
salvage yard, and sell for 50 cents to S3. 00, 
depending on the condition and whether or 
not you remove it from the wreck. 

The major enemies of auto clocks are 
moisture and dust. The latter is the most 
common but least damaging. In selecting a 
clock, pick one which shows no sign of rust 
on the face, hands» or any other exposed sur- 
face, and your chances of restoring it to ser- 
vice are almost a certainty. 

To remove the clock from the case pry up 
the edges of the bezel which holds the glass 
and remove these parts. Two or three small 
screws or nuts in the back of the case will 
now allow the clock to be removed. 

A large eye dropper or **ear" syringe will 
supply a low velocity air blast for cleaning. 
Do not attempt to use a brush, as fragments 
of the bristles will catch in the gears. 

The most common cause of failure is in 
the winding mechanism, so a complete des- 
cription of this operation is in order. On the 
back of the "works" is a rather large winding 
surrounded by a rotary armature. When this 
armature is aligned witli the winding, the 
clock is wound. As the clock runs down, the 
armature moves away from the poles of the 
winding, and, near the end of its travel, a pin 
on the armature engages a Y-shaped yoke and 
closes a pair of contacts. These contacts are 
in series with the winding and the voltage 
source, so when they close, the winding is 
energized and the armature is drawn toward 

118 



the poles of the winding. This rewinds the 
clock. This movement of the armature also 
opens the contacts by the action of the pin 
in the yoke. This contact between pin and 
yoke is where trouble develops. Just before 
the contacts close, the mechanism is at a point 
of maximum friction and minimum spring 
tension: so, with the collection of dust and 
evaporation of lubrication, the clock stops 
just shtirt of rewinding. 

After all traces of dust have been removed, 
apply a drop of solvent/lubricant of the type 
used for tuners and volume controls (Quie- 
troi, Spra Kleen, etc) to the yoke where it 
contacts the pin. Wind the clock by pushing 
the armature, and start it by lightly pushing 
the balance wheeL It will probably stop just 
before the contacts close- Without rewinding, 
start it again and let it run until the contacts 
do close. Rewind and repeat until it runs 
freely from rewind to point closure. Dry the 
yoke and apply a minute quantity of lubri- 
plate (a very light lubricant cream available 
from hobby and gun shops) to the point of 
contact with the pin. If desired a small am- 
ount of the solvent/lubricant can be applied 
to the pivots and teeth of each gear. The 
smallest drop you can get is sUghily too much 
for each point, so if you wish to skip this, 
the clock will probably run without it for 
years. 

The points may be cleaned with a burn- 
ishing tool, but avoid excessive filing. 

While the clock is "running in"' the power 
supply can be prepared. The transformer can 
be any, which gives the proper voltage. My 
clock used 12 volts, so a 6,3 and 5 volt wind- 
ing were connected in scries to give 11.3 
volts. This is plenty, since the winding is de- 
signed to work on 10-14 volts. The trans- 
former also has a ^>0V winding which is not 
used, so the leads are taped to prevent shorts 
and left hanging free. 

To determine the required voltage, look at 
the bulb in the socket which sits inside the 
case. If the bulb is missing, apply 6.3 ac be- 
tween the input terminal and frame, and ob- 
serve the armature. If it moves toward the 
poles of the winding (not necessarily all the 

73 MAGAZINE 



p 




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HATRY ELECTRONICS 

500 Ledyard St., HarfFord, Conn. 06114 

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Telephone: 203-5271881 

See CORKY, WIKXM or 
WARDr WIWRQ 

ANTENNA STUFF 



CODEMASTER tapes are Itmck monaural; available in two siies: /nnch reel (3% IPS) and ^^^-inch rael (l^i IPS), 
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way) use 6.3. If the winding buzzes and the 
armature doesn't move, the higher voltage 
will be required. 

When the proper voltage is found, let the 
clock run until it rewinds a few times to make 
sure all is well, then re-install it in the case. 
Most of these clocks have a cable clamp on 
the back which will make a convenient point 
for the ground connection, or a self-threading 
screw can be installed in a spot where it will 
not hit the works. 

These clocks come in a variety of sizes and 
shapes, and take naturally to panel mounting, 
or a small chassis or Mini-box can be used as 
a case. A switch may be installed to turn off 
the Ught, if desired, but the location of the 
bulb is such that it illuminates the clock face 
and little else, so it is left on in my installa- 
tion. 

The transformer can be mounted in the 
case with the clock, or up to 10 15 feet 
away^ depending on your needs. Lamp cord 
m fine for this connection. 

This will not bring National Bureau of 
Standards or even IBM into the shack, but it 
is a reasonably accurate timepiece, and the 
price is right, 

..,W0EDO 



In 100 foot roTU only 

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1 4 Copperweld. Per 100 feet * , , • 

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Times T4^50 L Loss 8U. Per foot ..,••.,, 18 

Tifnes T5'50 L ^ Loss 58U. Per foot * . -10 

irmes Solid Sheath A'umafoam in stock 

Kft& with connectors 50 100 ft 

Glass Line^guv wire. Per 100 feet 500 lbs Test 3.52 

Glass Line-guy wire. Per 100 feet 1000 lbs Test 5.27 

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MAY 1969 



119 



d 



I 



4x150 




Larry Jack, WA3AQS 
7421 Cwynndale Drive 
Clinton, Maryland 20735 



It was about a week after completing the 
small sideband rig that I realized its single 
watt wasn't going to be enough. After a 
few, 'You're readable, but kind'a weak" sig- 
nal reports, I returned to the junk box, this 
time for parts to build a linear. From a- 
mong the assorted trivia were unearthed a 
handful of 4xl50's. Two hundred watts 
output at least -a very good tube for the new 
amplifier but I didn't have any sockets for 
them. Being a little impatient to get start- 
ed, and adventurous at heart, I elected to 
build the sockets rather than wait out an or- 
der from a supply house. 

A simple modification of a regular octal 
socket provided a new base. A ceramic type 
(for its low losses) was selected. Then all the 
metal pins were carefully removed from the 
collar. The pins are crimped to make firm 
connections with the new size pins of the 
4x150, and then are replaced back into the 
socket. 



-♦FLARED EDGE 




.GR ID CONNECTOR 
FIGURE t 

A grid connector was made by flaring the 
top of a semi-circle of sheet metal about I'A 
inches high (Fig. I). This connector was 
placed into the socket key so that the gap 
between the semi-circle lines up with the 
slot in the key of the base. To prevent the 
connector from slipping out again, solder 
was melted about it, on the underside of the 
new tube base (Fig. 2). For cooling, the 
tubes were placed almost directly in the 
mouth of a large squirrel cage blower. 

I originally had used only a single .01 jjlF 
capacitor soldered directly at the socket pin 
as the screen by-pass. The rig took off, so 
to speak, in a very unstable fashion, so small 
straps on a standoff insulator with another 
.01 ;xF capacitor was put above the chassis 
to by-pass the tube's screen ring. This cur- 
ed the trouble (Fig. 2). 

Cooling never figured as a problem. At 
50 MHz with inputs reaching 600 watts, a 



SCREEN RING 




FIGURE 2 




FIGURE 3 




fhtlMPt 4 



single 200 cfm blower has kept a pair of one- 
fifties running cucumber cool. Not so many 
"kind'a weak" reports now. 

...WA3AQS 



120 




73 MAGAZINE 



RF Sealing Tape 

RF sealing is one of the strategies em- 
ployed in building transmitters that do not 
generate TVL The unwanted rf is generated 
but the enclosure is designed so it never gets 
out. 

The same approach is used to build 
receivers that do not respond to any rf 
except that which enters the receiver 
through a coax connector, and in the con- 
struction of laboratory signal generators. 

But did you ever try to convert a non- 
shielded enclosure into a shielded enclosure? 
It can be done, but ;ften it is a task to make 
strong men weep. Hinges, joints, ventilation, 
doors, meters^ , . , and how about shielding 
some of the wiring that carries power 
through areas hot at r/? 

Scotch Rescue 

The 3M Company has developed a re- 
markable copper foU tape with an elec- 
trically conductive pressure sensitive ad- 
hesive. The tape adheres directly to clean 
metal with a good low resistance electrical 
connection between metal and copper foiL 
The tape can improve leaky shielding by up 
to 60 dB. It is designated ^'Scotch" Brand 
Electrical Tape No. X-1 18 1 and comes in 54 
foot rolls of assorted widths* 

The tape is used alone* or with perforated 
or solid aluminum sheet. The sheet is avail- 
able in most hardware stores. It is cut into 
sections, shaped to fit, and taped in place. 
Large shielding assemblies can be made up 
from smaller ones. You must wash the 
aluminum with detergent to get any oils off 
before taping. 

One approach to reducing rf pickup by 
power or control wiring in transmitters is to 
use shielded wire. This is horrid stuff to 
work with, if you have ever tried it. A piece 
of ordinary tiookup wire can be laid along 
the chassis and covered with a strip of shield 
tape, to achieve the same result. 



FINAL SHIELD 




FOlt TAPE 



CHASSIS 




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CHASSIS 



Donald Kerr, WA3BDI 
State College, Pennsylvania 



DUAL GATE MOSFET 

PRE-AMPS 




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to 300 MHz. $23-95 ppd. 

to 400 MHz. $27.95 ppd, 

to 450 MHi. $31.95 ppd. 

• Available from 5 MHi, fo 450 MHi, Bandwidth Is 
approximately 3% of frequency, 

• Voitage gain 30 to 40 DB depending on frequency. 

• Two Dual Gate MOSF£T ampfifler stages with each 
having a tuned Input and tuned output. Each Dual 
Gate MOSFET Is actually an Integrated cascade cir- 
cuit thus giving you 2 cascode circuits equivalent 
to 4 triodes, 

• Exceptionally tow noise (2.5 OB at ITSMHi.), great- 
ly reduced cross modulation and 10 times the dy- 
namic range [signal handling capabflHy) of the best 
bi-polar transistors. Also superior to preamps using 
junction FETs and Single Gate MOSFETs. 

• Internal connections for high impedance AGC or 
manual <^atn control if needed* 

• Type BNC input and output receptacles for mifiimum 
loss at UHF. Standard Impedance Is 50-75 ohms* 

• Carefully tuned at our laboratory with sweep genera- 
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istic. 

• Full wave UHF diodes protect input transistor, 

• Operates on £ to 16 volts DC, 5 to 15 Ma. 

VANGUARD LABS 



Depti 
1 96-23 Jamaica Ave.i 



NY 11423 



"TOWER HEADQUARTERS!" 

11 Brands! HEIGHTS aluminum 35% off! 
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GO VHF 



Go VHF the easy VHF Associates way. Send for deicrlptlve 
Technical Bulletins describing our complete line of TRAN- 
SISTOR RECEIVING CONVERTERS and VARACTOR 
FREQUENCY MULTIPLIERS for 50, 144, 220. 432 ind 
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VHF ASSOCrATES, INC* 

P.O. iox 22135. DENVER, COLORADO S0222 



* 



i 



MAY 1969 



121 



i 



I 



Alan Shawsmiihr VK4SS 
35 Why not Sr West End 
Brisbane, Queensland, Australia 




All Band Curtain 




1.75 to 30 MHz 



(T'4 



[7' 4' 



TRANSPOSE 



■ j^ ^ 



29 6 



29'6' 



i ^m 



tr4 



PHASE 
REVfRSAL 




\\ 



600 OHM 
FEED 



17 '4 



ZS'B' 



OO MOT 
TRANSPOSE 



zg'G" 




I 7 '4^' 



TRANSPOSE 



I7'4 



Fig* 1* Dimensions for the bW band curtain array^ 



Looking for something better than a ran- 
dom length flat top for your multi-band op- 
eration? This pint sized array which puts 
out a big signal should more than provide the 
answer. After some cut and try trials, the 
configuration shown in Fig. 1 was decided 
upon as the best all band result- It repre- 
sents an attempt to get the most with the 
least outlay- All that is required over a flat- 
top is some extra wire and insulators- It 
should be easily erected on any average lot, 
as the total length between poles is approxi- 
mately 112 feet. It has superior gain over 
most flat-tops on 14, 21, and 28 MHz. Its 
low angle of radiation being one feature. If 
it is not possible to erect it to its full length, 
the 8 foot spacing at the transposed sections 
can be reduced somewhat with slightly less 

gain available. 

On 1.75; and 7 MHz respectively, it really 
performs as a quarter, half, and 2 half waves 
in phase. However, the configuration at 7 
MHz does add some gain and lower the angle 
of radiation slightly. If DX is desired on 
these bands, the bottom wire must be at least 



30 feet above ground and preferably much 
more. For DX on 14 through 28 MHz the 
bottom wire should be a minimum of 20 feet 
above earth. On 28 MHz, there are some 
8 wavelengths of wire up in space which adds 
to the signal. 

Maximum radiation is mainly broadside on 
bands L75 through 21 MHz. It throws the 
sharpest beam with the most gain on the lat- 
ter band, while on 14 MHz, the pattern is 
broad and something in shape like a three 
leaf clover on either side of the axis. No db 
measurements have been attempted, bul iLs 
performance is far superior to a random 
length wire used at the same QTH and strung 
at a comparable height. Since it is horizon- 
tally polarized, the higher the array is strung 
up, the better. 

Being multi-band, no attempt can be made 
to match the 600 ohm feedline. which can be 
any length, but may have to be pruned if the 
array is reticent to accept power on any one 
band. A flexible aU band antenna tuner is a 
must for proper loading, 

-.VK4SS 



p 



122 



C 



73 MAGAZINE 



A. E. McGee, Jr., K5LLI 
281 5 Materhorn Drive 
Dallas. Texas 75228 



How To Tune A Circuit 

In these days of intricate and relatively 
inexpensive commercial radio equipment, 
home building of ham gear is not so com- 
mon as it used to be. However, a great deal 
of pleasure and satisfaction may still be had 
from the designing and building of simple 
receivers, converters, etc., even if you never 
intend to actually use them on the air. 

One fairly critical part of most simple 
projects is the tuning circuit. At frequencies 
through the VHF region, a tuning circuit 
usually consists of an inductor (coil) and a 
variable capacitor, wliich is adjustable over a 
reasonably wide range. It is easy to find, by 
the trial and error method, some combina- 
tion of inductance and capacitance that will 
tune to the desired frequency. The trouble 
usually begins when you try to band-spread 
the circuit; that is, to make the entire tuning 
range of the variable capacitor cover only 
the desired frequency range. This frequency 
range may be only several hundred kilo hertz 
wide, such as an amateur band or a short- 
wave broadcast band. 

This article will attempt to illustrate the 
problems involved, and how to solve them 
by the use of a grid-dip oscillator and some 
simple charts and formulas. First, however, a 
few words about circuit theory may be in 

order. 

An inductor or a capacitor will oppose 

the flow of an alternating current. This 
property is called reactance, and differs from 
resistance in that the current through the 
reactance is 90 degrees (or one-quarter 
cycle) out of phase with the voltage. In an 
inductor the current lags the voltage by 90 
degrees, and in a capacitor the current leads 
the voltage by 90 degrees. The amount of 
reactance is determined by the value of 
inductance or capacitance, and by the fre* 
quency of the alternating current. Inductive 
reactance increases with an increase in fre- 
quency, wliile capacitive reactance decreases 
with an increase in frequency. 

When an inductor and a capacitor are 
connected, either in series or parallel, there 
will be one frequency at which their react- 
ances are equal. Since the inductive react- 
ance causes a current lag of 90 degrees, and 
the capacitive reactance causes a current lead 



PF 



MHt 



UH 



10 



zo 

40 
50 

70 
BO 
90 
100 



ZOO 

300 

400 

500 

soo 



100 
90 
BO 
70 

SO 

so 

40 
30 

20 



10 

s 
& 

1 

G 



3 

04 
05 

oe 

0.7 

Ofl 
OS- 
J 



S 

7 
8 

9 
10 



Fig, 1, Resonant frequency chart. By lay- 
fng a straight edge across two known quan- 
tities, the third cbt\ be deternnined. 

of 90 degrees, the reactances cancel each 
other, and the circuit is said to be in 
resonance- The series resonant circuit offers 
a very low resistance to the flow of alter- 
nating current at the resonant frequency, 
and the parallel resonant circuit offers a very 
high resistance to the flow of alternating 
current at the resonant frequency. 

The frequency of resonance may be 

found by using the formula:f=27?w1c' ^^*^ f in 
Hertz, L in Henrys, and C in Farads. A 
simpler method is to use a chart like the one 
in Fig, I, By laying a straight edge across 
two known values, the other quantity may 
easily be found. Charts covering a wide 
frequency range may be found in Allied 's 
Electronic Data Handbook and other similar 
publications. There is also a chart on page 70 
of the August 1 967 issue of 73 Magazine- 
Let us say that you wish to build a circuit 
that tunes from 7,0 MHz to 7,3 MHz. You 
have a variable capacitor from the junk box 
that you wish to use, a few surplus coils with 
unknown inductance values, and an assort- 
ment of small fixed capacitors. You also 
must have a calibrated grid-dip oscillator* 

In order to find the capacitance of the 
variable capacitor, you will first need a 
known value of inductance. Pick a likely- 
looking coil from the junk box, or wind one 

by guess or by using a coil winding chart. 
The chart found in AIlied*s Electronic Data 



^ 



MAY 1969 



123 



Handbook is easy to use and accurate for 
coil diameters from Vi inch to 5 inches. 
Connect a fixed capacitor with a known 
(marked) value across the coil and find the 
resonant frequency of the combination with 
the grid-dip oscillator. If possible, use a mica 
capacitor with a 5% or 10% tolerance. Let's 
say you use a 100 pF capacitor and the 
resonant frequency is 9.2 MHz. By laying a 
straight edge across these two values on a 
resonance chart (Fig. l), the inductance of 
the coil is found to be 3 uH. 

The 3 uH coil may now be used to 
measure the minimum and maximum capac- 
ity of the variable capacitor. Connect the 
coil across the variable capacitor and meas- 
ure the resonant frequency at the minimum 
and maximum capacitance settings. If the 
resonant frequency is 20 MHz at the mini- 
mum setting and 5 MHz at the maximum 
setting, the variable capacitor has a range of 
about 22 pF to 350 pF, 

You will note that the frequency ratio (4 
to 1) is equal to the square- root of the 
capacity ratio (16 to 1). This is important to 
remeniber, and is true also for the induct- 
ance ratio when the capacity is held con- 
stant. Thus, in the circuit above, if it were 
desired to bring the lowest frequency down 
from 5 MHz to 2.5 MHz, a 2 to 1 frequency 
ratio, the capacity or inductance would have 
to be increased by 2 squared, or 4 times 
(1400 pF with 3 uH, or 12 uH with 350 pF). 

Now that the variable capacitor has been 
measured, a coil can be chosen that will tune 
the desired 7.0 to 7,3 MHz range. It may be 
seen, by checking our resonance chart, that 
the 3 uH coil used in measuring the variable 
capacitor will tune to 7.0 MHz with about 
175 pF, and to 7.3 MHz with about 160 pF. 
As this is well within the range of our 
variable capacitor^ we may as well use it in 
our circuit- 
Band-Spreading 

Although our circuit will tune through 
the range of 7.0 to 7.3 MHz, the required 
capacity change of 15 pF would be covered 
in only a small fraction of a turn of the 
capacitor, and tuning would be very diffi- 
cult. This problem is easy to solve, however, 
by the addition of two more capacitors to 
the circuit. Since we need a variable capac- 
itor with a range of 160 pF to 175 pF, a 
capacitor may be added in series with the 
variable to lower the total maximum capac- 
itance from 350 pF to 175 pF, and a 
capacitor may be added in parallel with 
these two to raise the minimum capacitance 



from 22 pF to 160 pF, See Fig, 2, The series 
capacitor is called a padder and the parallel 
capacitor is caDed a trimmer. 

The value of the trimmer should be 
determined first Its approximate value can 
be found by subtracting the minimum 
capacitance of the variable from the desired 
minimum capacitance. Thus 160 pF minus 
22 pF equals 138 pF for the trimmer. The 
value of the series combination of the 
variable at maximum capacitance and the 
padder is equal to the total desired maxi- 
mum capacitance minus the trimmer capac- 
itance. Therefore 175 pF minus 138 pF 
equals 37 pF for the combination of the 
variable (set at 350 pF) and the padder The 
value of the padder may be found by the 
formula: Cl=CtC2/C2"Ct, where CI is the 
padder, C2 is the variable, and Ct is the 
desired total This works out to 41 pF for 

the padder. 

Since the padder is only about twice the 
value of the minimum capacitance of the 
variable, it will have a noticeable affect on 
the total minimum capacitance, making it 
152 pF instead of the desired 160 pF, This 
difference will be more than made up for, 
however, when other parts of the circuit are 
connected to the tuned circuit. Stray circuit 
capacitance and the input or output capac- 
itance of the tube or transistor used will add 
from 5 to 10 pF or more to the total 
capacitance. At the higher frequencies this 
becomes increasingly important, and should 
be allowed for. 

When building a circuit one stage at a 
time, remember that when the following 
stage is connected it will upset the output 
tuning of the previous stage. It may be 
helpful to connect a small value of capac- 
itance temporarily across a tuned circuit that 
will later be connected to another stage. 
When the other stage is connected you can 
remove the capacitor. At high frequencies, 
where the adjustment range may be small, 
this may keep you from having to rewind 
the coil. 

A good type of capacitor to use for 
trimmers and padders is the adjustable mica 



n 



132 TO 



1 



41PF 



2ZT0^50 



t38Pr 



Ftg, 2. The 22 to 350 pf variable capacitor 
is effectively changed to 152 to 175 pf by 
the addition of two extra capacitors. 



124 



73 MAGAZINE 



§" 




fl 



I added a linear." 



compression type. These are small and inex- 
pensive, and come in sizes ranging from 
about 1 pF to over 3000 pF. The minimum 
to maximum capacitance ratios vary from 
about 10 to 1 in the small sizes to about 2 to 
1 in the largest sizes. When using adjustable 
capacitors set the high frequency limit with 
the trimmer, and 'the low frequency limit 
with the padder. Since the adjustments 
affect one another they may have to be 
repeated several times. If maximum stability 
is important, fixed silver mica or adjustable 
air capacitors should be used. 






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Box 322, Angola, Indianer 46703 
Phone 219 665-2901 Eves Only 



I have not mentioned circuit Q. This 
quantity is important in the output circuit 
of transmitters, in circuits where maximum 
selectivity is important, and many other 
places. However, in most simple low-power 
circuits the Q may be safely ignored. 



ARE YOU PAYING 75c A COPY OR 33c? 

Righto * . * that's 33c a copy lor 73 when you buy if In three year batches. Figure 
it out. 36 lovely issues of 73 for $12. Send cash, cheeky MO, 

All subscriptions will start with the February issue unless otherwise 
specified. 



ame 



I 

I N 

1 

[ Address 



-.Call 



,Stat- 



Zip ^ 



if 



I I prefer fo be a subscriber .._„„, „— $12 for three years 

D i am a cheap microscriber ..„,..„.„.._$ 6 for I very shorf year. 



These rates are 
valid world-wide 
yntit we ^ise up. 



I 

j 73 MAGAZINE PETERBOROUGH. NEW HAMPSHIRE 03458 



MAY 1969 



125 




TEST EQUIPMENT 



MINIATURE TEST LABORATORY 




AC Voltmeter 

Ohmmeter 

RF Signal Generator 

Resistance Substitution 

9V DC Supply 

Self Powered 



DC Voltmeter 

Milliammeter 

AF Signal Generator 

Capacitance Substitution 

RF Field Strength 

7%"x 3%''x 3%*\ 1% lbs. 



Thanks to transistors and printed circuits you can 
hold this complete lab in one hand. Not long ago 
this would have been a whole shelf full of test eq- 
uipment, 455 kHz generator for aligning IF's, 400 
Hz generator for audio circuits. Plus a normal VOWl 
and R & C substitution. Field Strength meter for 
tuning transmitters. Everything in one small box! 

Model SE-400 Mini Lab - ONLY $25.00 

TRANSISTOR FOWEK SUPPLY 




Worth its weight in batteries. Invaluable for testing 
transistorized or 10 gear. Saves its price in batteries 
for long range operation of radios, cassette tape re- 
corders, etc. 0-20 VDC @ 150-200 mA. Metered 
and regulated. 

Model SE-100 Power Supply-ONLY $16.95 




P.O. Box 
JAFFREY, 
03452 



NH 



lliv (lav (jf Uie ^^real bi}i fpirre tpf 
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ory by tuodrrn Imnmlorizvd l*( Ivsl 

m-^ m-- 

rqaipniniL \(HV a conifflvte Hprnn' 
IuIk itichtiling Hf and AF sip:ti(d p'nrr- 
(ilors. is ha ill into a vase aboul I lie 
sizr of an (dd \ OMl 

MINIATURE AF GENERATOR 




Mini-AF Generator for the laboratory or ham work 
bench. 10 to 100,000 Hz in four bands, sine or 
square wave. World's smallest, lV2*x 3%"x 4", 
2 lbs! Built-in AC power supply stabilized to 0.1%, 
The output is maintained at minimum distortion 
and constant level with FET oscillator and therm- 
ister and heavy inverse feedback. 

Model 6803 AF Generator - ONLY S59.95 



MINIATURE 
SIGNAL 
TRACER 

This is by far the 
single most valuable 
piece of test equip- 
ment for servicing 
receivers and audio 
equipnnent. Built in 
meter for measuring 
gain of each stage 
under test. Easy to 
find weak or defect- 
ive stages. Output 
speaker built in or 
to VTVM or scope. 
No line cord since it 
is self powered. 

Model SE-350 Signal Tracer-^ONLY $22.50 

Buy DGP Miniature Test Equipment from 
Your Local Distributor or Order Direct Mail 
from REDLINE CO, JAFFREY, NH 03452 
Please allow a little extra for postage charges. 

Distributors: Write for our distributor prices 
Manufacturers Reps: We need you -Write 




126 



73 MAGAZINE 



p 



SSB Escalator - Part II 

Since the original article on r/SSB speech 
clipping appeared in 73 Magazine (p, 16, 
Dec, *66), I have received a number of in- 
quiries relative to the construction of the 
clipper unit. 

Resistors R3 and R4 in Fig. I should be 
interchanged (this was a printer's error). Re- 
place the 300S1 cathode resistor of V2 with 
one of 68n and the 47k screen resistor with 
one of 20k. At the grid input of VI the 22k 
resistor is omitted and a 140 pF APC vari- 
able capacitor is substituted for the fixed 
180 pF condenser for maximum tuning of 
the signal. Mount the mechanical filter top- 
side with its midpoint baffle shield omitted — 
an original but later-proved unnecessary 
precaution- 
It is important that the filter employed 
be identical to the one in the exciter unit- 
If the carrier frequency is not down on the 
filter skirt at or very close to that in the ex- 
citer unit, one of two undesirable things will 
take place: either the lower voice frequen- 
cies will be out of range of the passband and 
the audio will sound tinny, or insufficient 
sideband rejection of the lower clipped voice 
frequencies will occur with unwanted, newly 
generated frequencies. It may be preferable 
to extract the r/ signal at the output of the 
balanced modulator rather than at the out- 
put of the following f/ stage. In place of the 
original Millen // transformer, Tl, try a less 
expensive one; T2 may be a Miller 912-C4 
// transformer. The .01 mfd coupiing con- 
denser in the secondary lead of T2 may be 
left out* 

The power supply can be placed on the 
same chassis with the clipper unit although 
a larger chassis, of course, will be required. 
Any power supply system that will deliver 
from 30 to 50 mA at a regulated voltage of 
105 to 150V will be satisfactory. 

The following simplifications may be 
made: Omit the sub-miniature switch, SI, 
and run the two RG-174/U coax input and 
output leads directly to the two jacks men- 
tioned in the paper, A short coax-cabled 
Jumper between the two jacks will restore 
the original exciter operation- Omit both 
the no-clip gain control and the DPDT 
switch, S2- Simply rely on the clip level 
control to adjust the amount of rf clipprng. 
If excessive hum is encountered when 
clipping, it may, unfortunately, be necessary 
to shield the exciter's audio input stage. 

Louis Berman, K6BW 



r 

I 



NEW QSL BUREAU 

To handle all your QSLs, whether for next door, 
the next state, the next country or anywhere! 
IMo special membership fees^, coupons^ or rules; 
Just: 

M each for QSLs for USA, Canada or 

Mexico, 

44 each for QSLs for any other place in 
the world* 

Just bundle them up (piease arrange alphabet- 
ically) and mail to: 

WORLD QSL BUREAU 

5200 Panama Ave. 
Richmond, Calif. U.S.A. 94804 

Attention Hams USA, Canada and Mexico — 
Yes, we mean just what we say— at last a QSL 
bureau to handle QSLs for QSOs within your 
own country, 

Attention Hams outside USA, Canada and 
Mexico (and SWLs anywhere). Please send us 
your QSLs for defivery anywhere— same rates 
as listed above. 

Attention Radio Clubs. Here fs a way to in- 
crease attendance at your club meetings. On 
application we will send QSLs received for 
your members to you for distribution at meet- 
ing. Also special plan at reduced cost for out* 
going QSLs from clubs available. Send for de- 
tails. 



''CHOICE OF THE DX KINGS'* 




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B Fiberglass Arms— skybfue color 

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16 Wraplock Spreader Arm Clamps 

1 CU8EX QUAD Instruction Manual 



$59 



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Add $a.50 for PPD 
Frt Cont. U.S. 



2-3-4 or more element Quads available 
Write for FREE BROCHURE 'G'ft Price List 

CUB EX COMPANY 

P.O. Box 131, Altadenap California 91001 
Phone: (213) 798-8106 

YOU CAN'T SAY "QUAD" BETTER THAN "CUBEX' 



1 



MAY 1969 



127 



] 



r 




SQUEEZE ACTION TOOL 

A MUST fm JHE MECHANIC 



NEW PRODUCTS 







Heath 2 Meter Transceiver 

The latest in a growing line of ''single 
banders" has come out of the Heath Com- 
pany, This new unit, the model IIW-17, 
covers the amateur two meter band and also 
has facilities for the MARS and CAP fre- 
quencies* Crystal controlled, the output is 
about 10 watts AM* 

The dual-conversion solid state receiver 
has 1 microvolt sensitivity and features a pre- 
aiigned FET tuner, ANL, Squelch, ^'Spot" 
function, lighted dial and a relative power 
putput meter- It comes with a built-in AC 
power supply and microphone* The DC sup- 
ply for mobile operation is optional at 
$24^95. Priced at $129.95, this is a best buy 
item. For further information, write Heath 
Company, Benton Harbor, Michigan 49022. 

SQUEEZE ACTION RATCHET WRENCH 

Fulfills tlie ruciuirements of professional 
antl home mechanics. Tri hard to reach areas, 
tuniing is accomplislied by merely squeez- 
ing spring loaded scissor t\pc handle. Where 
there is more room it can be operated lilce 
a conventional ratcheting box wrencli* For 
reverse action, just turn the tool over. Box 
socket is Ji", Twelve hex inserts range from 
K" thru "^Mi" and millimeters frcmi 6 nun thru 
11 mm. A rubber friction lock keeps tlie 
insert firmly in position. Retail S12.95, 

For further information contact THE 
JAY THOMAS COMPANY. 117 West Ox- 
ford Street, Dept. \LXL-5, Chula Vista, 
Calilnrniii 9201L 




AUTOMATIC TOOLS 



Pioneer 300R Audio 
Frequency Standard 




The Pioneer 300R is a higlily stable secon- 
cary frequency standard of completely solid 
state design, using quartz resonators for sta- 
bility. It functions as a tone receiver or tone 
transmitter. The stability is .005% and 
switching allows selection of up to three stan- 
dard frequencies. It provides a built-in atten- 
uator for receive appHcations. 

It can be used in the receive mode for 
calibrating oscillators directly without the use 
of an oscilloscope or other indicating device 
normally needed with a standard to indicate 
zero beat, it is an indispensable piece of 
equipment for RTTY, and a valuable cahbra- 
tor for oscillators, oscilloscopes, and bridges. 
Accurate inductance and capacitance mea- 
surements can be made using this precision 
source. To guarantee stability over a wide 
range of temperatures, the resonators are kept 
at a nearly constant temperature in an insul- 
ated and shielded oven. The oven comes a:^ a 
sealed unit with desired resonators included 



128 



73 MAGAZINE 



inside. Additional frequencies may be ob- 
tained for $35 each. 

For further information write Pioneer El- 
ectronics, 738 Pacific St,, San Luis Obispo, 

California 9340 L 




Linear Systems, Inc. 

David C. Thompson, President of Linear 
Systems, Inc*, has announced the election of 
David K. Bradley as Vice President, Marketing 
for the firm. Mr. Bradley previously was Na- 
tional Sales Manager for the SBE line of ama- 
teur radio products at Raytheon Company, 
South San Francisco, California, He has been 
active on several EIA committees in the ama- 
teur and citizens band business. Mr, Bradley 
is well known in the amateur radio fraternity 
and has the amateur license W6CUB. Prior to 
joining Raytheon, Mr. Bradley owned and op- 
erated an amateur radio distributorship in 
Northern California. Mr. Thompson stated that 
Mr. Bradley brings a unique combination of 
technical and marketing experience to the com- 
pany. This capability fits the needs of Linear 
Systems, Inc., which Mr. Thompson stated 
plans to become a broad based communications 
company. 

Optiflex 

Fiber optics is that light-piping idea you 
have been reading about sometimes over 
tlic past few years, IBM uses fiber uptic de- 
\'ices to pipe liglit to convenient corners of 
their card-reading machines, eliminating 
many individual lamp assemblies. Now the 
idea is appearing in service gear. 



Amertest Products' handy little lamp con- 
sists of a conventional penlight plus a flexible 
fiber optic cable. The cable really is flexible 
enough to tie into knots. It's a nonconductor, 
toOj so that you can poke it into li\"e cir- 
cuits and assemblies witliout concern about 
new unwanted connections inside the gear 
or out to ibe real w^orld, incKiding your- 
self. Just right for getting some light into 
those dark corners. 

Suggested list price on the Optiflex lamp 
is $4.65. For additional data inquire at your 
dealerX ox write to Amertest Products Corp., 
144-27 Jamaica Ave,, Jamaica, LJ.^ NT. 
11435, 

AMD Microphone 

If you are interested in outdoor amatexir 
operating, serious un-location tape record- 
ing, in speech work, or public speaking ap- 
plications, here is a microphone that may 
well be a Best Buy. 

Since it is a cardioid microphone it has 
a strong null toward the cable-attachment 
end. This avoids crowd noise problems, and 
greatly alleviates the nuisance oF audio feed- 
back in public address applications. 

For outdoor tape recording and amateur 
operating, its built-in windscreen styling re- 
duces or eliminates the need for tlie fre- 
ciuently-vseen large x>lastic foam cover. And 
the microphone's 100 to 12,000 Hz response 
is adequate for all speech aiid some musical 
applications. 

Special connector wiring in the micro- 
plione stem olters the user a choice of 600 
ohm impedance (-73 db sensitivity) or 50K 
ohm impedance (-54 db sensitivity,) It has 
an uu-otf switch, and comes with 20 feet of 
cable with a standard phone plug, and a 
swi\ el microphone stand connector. 

Priced at $13.95 retail, from AMD Elec- 
tronics, 663 Dowd Ave,, Elizabeth, NJ, 
0720 T 



FCC Recognizes 
Thailand— Almost 

The FCC has announced that it is 
now permissable to contact stations in 
Thailand using U,S. calls/HS. Commun- 
ications are still prohibited with the HS 
prefix stations. 



MAY 1969 



129 



4 






Adapting A Mobile 



System 



Antenna 



M 



Ihcati 



ion 



Use 



Bud Michaels, WB2WYO 

510 High Street 

Viator, New York 24564 

A last-minute decision to take a rig along 
on vacation left me with the problem of what 
to use for an antenna. We would be moving 
from campsite to campsite every few days, so 
my inherent laziness precluded an elaborate 
antenna system. Likewise, I didn't have much 
enthusiasm for disturbing three years* accum- 
mulation of rust and crud to dismantle a mo- 
bile whip antenna, offered by a friend, along- 
with a complete set of resonators. 

After much consideration^ the mobile sys- 
tem seemed the most practical, and I accept- 
ed the loan of the resonators, but struck out 
on my own to devise a whip and base; one 
that would allow me to use the resonators, 
yet not necessitate tying the car down at the 
campsite. 

The problem was solved using EMT elec- 
trical conduit- A whip, base and supports/ 
ra dials were made using Vi'' diameter conduit 
and a square junction box. The whole affair 
cost less than $5.00 and proved to be a truly 
effective and simple antenna system. In fact, 
Tm collecting my own set of resonators in an- 
ticipation of next year's vacation. 

Making the Whip 

Cut a piece of !4" diameter conduit to 
54 *\ (This dimension is for Newtionics reson- 
ators. For other resonators, rely on manufac- 
turer's specs or measure a friend's antenna,) 
A pipe cutter does a neater and faster job than 



OCTNL m 



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fiiJ^f IF 



juji e<TAj|, 




Antenna set up in front yard of author's home for 
SWR measurements* Additional ground was re- 
quired for 40-meter operation. 

a hacksaw. File away the burrs at both ends, 
then brighten up the metal inside one end of 
the conduit so it will take solder, 

FUe the edges off the head of a 3/8"- 24x 
1" bolt, and a 3/8"-24 nut so they wiU fit 
snugly into the conduit. Thread the nut onto 
the bolt, leaving W of the bolt extending. 
Tin the bolt and nut, then shp them into the 
conduit with the nut flush with the end of 
the conduit- Solder them in place- This forms 
the means of attaching the resonators to the 
whip. 

The whip must be insulated from the base. 
This is done using a Vi" to Vi"" plastic water 
pipe coupling. Cut a short piece of conduit, 
around three inches long. Clamp this in a 
vise and warm with a torch untO you can force 
the plastic coupling in. Quickly cool the as- 
sembly, lest the heat distort the coupling. Do 
the same with the bottom of the whip, so 
when finished you have the plastic coupling 
(our **insuIator") between the whip and 
stub. The plastic coupling will most likely 
slip out of the conduit, and epoxy cement 
or "pop" rivets can be used to make the joint 
more permanent- 



130 



73 MAGAZINE 



I found it more convenient to attach an 
SO-239 connector so that the coax cable 
could be more easily connected. Details are 
given for making a bracket to mount the con- 
nector. (Naturally, this idea cam^ after vaca- 




End view of whip showing the 3/8-24 bolt which 

screws into mobile- antenna resonators, 

tion!) The center wire from the connector 
is soldered to the conduit through a hole 
made for the purpose- If you do not wish to 
use a connector, the coax can be soldered 
directly to the whip; the shield being soldered 
to the stub. 

Base 

The base is made from a 4'' square elec- 
trical junction box. Be sure to use one with 
W knockouts. Five Yi'' conduit connectors 
are screwed into the knockout holes, as 
shown, with their screw heads facing upwards, 
Don*t overlook this simple point, otherwise, 
it will be awkward to disassemble the anten- 
na for take-down. Here's another bit of 
hindsight: the top of the junction box is not 
too sturdy, owing to the knockouts stamped 
in the metal. Make a plate to fit over the top, 
as shown in the illustration- Screw or rivet 
this reinforcing plate to the box, then install 
the center connector. You will find this ar- 
rangement holds up much better, especially 
if you anticipate small boys will be using your 
antenna for a "Maypole,'' 

Support— Radials 

The four suppofts/radials are made from 
five foot lengths of conduit. Five feet is a 
convenient length to carry, and two can be 
cut from one 10-foot length of conduit (stan- 
dard length). Don't make them any shorter, 
or mechanical stability and antenna radiation 
will suffer. If you can make them longer, so 
much the better; especially if you intend 
doing any work on the 80 and 40 meter 
bands. 

Setting Up 

Using the antenna system is simplicity it- 



self. Place the four radials into the connec- 
tors and tighten the screws securely, yet not 
enough to deform the conduit. Attach the 
whip to the center connector, then screw the 

resonator to the top of the whip. Follow the 
manufacturer's instructions for adjusting the 
resonator to the lowest swr. I did have troub- 
le bringing the swr down on the 75 meter re- 
sonator, due to poor ground conditions. (Af- 
ter all, five foot long radials at 75 meters is a 
joke!) The problem was relieved somewhat 
following a suggestion by WA2A0D: use 
kitchen aluminum foil swiped from the XYL 
to increase the ground plane. Four 15' long 
strips placed under the radials helped get my 
signal out with acceptable performance. 




View of the base. These were taken before the re- 
inforcing ptate, mentioned in the text, was added. 
Coax bracket is held to base with "pop" rivets. 

Some Other Ideas 

The success of this arrangement prompted 
me to do some experimenting after we 
returned home. Using the same base, 1 made 
an 18' vertical antenna using one 10' section 
of conduit, joined with a regular W^-to-W^ 
coupling. The antenna was base loaded with 
a coiL While the junction of the two lengths 
of conduit was not the strongest, I did man- 
age to keep the antenna up all weekend and 
worked quite a few stations on 80 and 40 
meter CW, (This, by the way, was done after 
the junction box top was reinforced as des- 
cribed above.) As a practical limit, it seems 
that 20' is the maximum height for conduit 
^'verticals'' because of the lack of rigidity at 
the joints. If you could come up with a 
stronger joint, I imagine these might serve 
admirably for field day use, with a minimum 

of guying. 

...WB2WY0 



d 



MAY 1969 



131 



LETTERS 



This is in response to your letter of February 
19» 1969, concerning the implementation of the 

second phase of the incentive licensing frequency 
reservations. In establish] n£ the time scftedule for 
the reservations of frequencies in Docket 15928, 
the Commission states that "Notwithstanding this 
schedule, the Commission intends careful reviev^^ 
and if it is determined that tlicre is insufficient oc- 
cupancy of any part of the reserved frequency seg- 
ments, then the effective date of the implementa- 
tion date will necessiarily be stayed in whole or in 
part, as appropriate." This statement has been re- 
iterated in a number of Commission actions since 
the determination in Docket 15928- 

A petition (RM 1393) is on file requesting the 
Commission to rescind that portion of Docket 
15928 which would reserve additional frequencies 
in the 7 Mc/s and 14 Mc/s bands for Extra Class 
licensees. As previously stated* the Commission will 
review the occupancy of the segments now reserved 
and determine, prior to the November 22, 1969, 
scheduled date for implementation of the second 
frequeacv reservation* whether additional reserva- 
tions are justified. 

James E. Barr 

Chief, Safety and Special Radio Services Bureau 

F.C.C. 

Say Wayne, I just picked up 73 and liked very 
much your thoughts on incentive licensing. Your 
positive approach to this and other matters merits 
careful attention^ I also, of course, note your con- 
tinuing license study articles, which are by far the 
best that have appeared in ham publications. I 
have been helping some hams with some of the ba- 
sics for their licenses (I hope) and your articles 
have saved me some time of having to go into Ter- 
man or the ARRL handbook, etc. Thanks to you 
and your staff for publishing these articles and not 
just questions and answers as have some of the other 
magazines, 

Incidently, you mention other mags saying 
things about 73; yes^ I have read these and started 
adding certain things up: in fact, I went back several 
years in tlie various ham maga/Jnes and read about 
what is and was going on. You are right and they 
are wrong. Say, Wayne, do tell us all about the 
lARU, CQ. and other things that the amateurs are 
anxiously waiting to hear about. Don't be too 
harsh on the ARRL though, they are trying to do a 
good job handling all that traffic and keeping the 
nets on frequency and holding elections and parti- 
tioning the FCC and stuff like that there. 

Bob, W7JLU 
Portland, Oregon 

I consider 73 to be one of the finest magazines 
in the amateur radio field, or indeed, in any field. 
This is about the fourth year 1 have been reading 73 
regularly and I have thoroughly enjoyed each and 
every issue. 

In comparison to the tcchnistic platitude that is 
OST and the artiirtic mediocrity that isCQ, 73, like 
the farmer, is outstanding in its field. You have 



managed to keep a sense of humor throughout 
these times of peril for amateur radio in general. 
This is certainly a relief from the competition who 
feel that they can be dry and serious for 1 1 months 
out of the year if they make it up with a whopping 
April issue. 

In summary, then, 1 think 73 is the greatestt 
and I sincerely hope it can stay that way for many 
years to come. Above all, l can only hope and pray 
that your idea that ham radio is fun will have a re- 
birth among Uic electronistic and scientistic types 
whoVe pervaded the radiophonic world recently. 
My amateur Extra Class license notwithstanding, 
Vd rather chew the rag about music, ^Is^ politics, 
or UFO's than build my own self-neutralized class 
AB7 variable-prcbic amplifier module with limited- 
fidelity sideband autonizen 

Lon J. Berman^ WB21W1/2 

Open Letter 

If you did not read Wayne Green's excellent 
editorial in March 73 Magazine, you should have! 
It was timely, pointed and full of meat! 

Amateur Radio greatly needs the shot in the 
arm that a well-conducted Public Relations pro- 
gram could give- provided that the PR people are 
properly '^'Amateur-Radio-oriented!" ARRL des- 
perately needs a better image with the Radio Ama- 
teur, with the public and most of aU with the U.S. 
Government, to whom we owe our very existence- 
and continuence! 

Wayne mentioned certain writers and a cartoon- 
ist wlio could help. There are many qualified writ- 
ers in the field who could and would contribute 
articles and material to this endeavor, given the 
slightest oppoTtunity-and acceptance by editors. 

The capable Ray Meyers, W6MLZ, it has been 
reported, offered to serve ARRL as its PR man, 
for the customary SI a year, plus normal operating 
expenses. Ray^s qualifications need not be discus- 
sed here --they are completely adequate, and his 
devotion to Amateur Radio is well known through 
many years of dedicated service as a writer, lecturer. 
Director of ARRL, and columnist. Ray's generous 
offer was spurned by ARRL. Why? 

ARRL's feeble attempts at PR have been through 
NON-licensed-Amateur personnel. Although Don 
Waters did a commendable job on his reporting of 
ARRL's status -it lacked the touch of a genuine 
Amateur, fighting for his own hobby. 

This writer urges YOU to immediately contact 
your ARRL Director, by telephone or mail, and 
demand that ARRL institute a program of PR, 
witii a "man in Washington'* (a legalized ham- 
lobbyist) without delay. Let there be no referral to 
a committee or a "study by the Secretary to deter- 
mine the need" or other typical procedural jazz by 
the ARRL Board. Demand that the Directors, at 
this meeting, set up such a progrs-im and that they 
follow through to sec that it is done. As Green 
says, it may already be too late, but the effort must 
be made. Take action now! 

In reference to Wayne Grecn\ mention of band 



132 



73 MAGAZINE 



occupancy, a complete study should be made, by 
ARRL (or someone concerned with the progress 
and growth of Amateur Radio) to determine what 
changes are necessary and vital in regard to band 
usage. In the opinion of this uTiter, (a consistently 
active ham for 49 hears) the CW bands are loaded 
when contests are on-^and pretty empty at other 
times. The VHF bands are consistently empty, ex- 
cept during "openings*' or contests. Ten meters, 
formerly the work horse of casual rag chewers, 
shows fittle occupancy now. Such an occupancy 
study, plus recommendations, both qualified and 
studfed-to FCC— should result in changes, even 
though temporary, that would raise the occupancy 
of our empty bands segments and reduce the QRM 
in the other sections. 

There is nothing sacred about FCC regulations- 
They can and should be changed when the need 
arises and without long delays, hearings and other 
proceedings- 

ARRL should have a better relationship with 
FCC and be able to advise FCC when and how the 
band segments should be changed and redeployed! 
No one is served by holding to long usage concepts 
of the bands when it is obvious to anv active ham 
that changes are desperately needed. 

On this point, why are so many licensees who are 
now permitted to utilize the "restricted" segments, 
still holding forth in the clutteied-up sections? 

A, David Middelton, W7ZC 
Former ARRL Director 



With reference to certain aspects of the "de 
W2NSD/1" article in your March issue, you may be 
interested in the following information- 

In the April 1967 QST, there appeared a re- 
quest that members advise their Directors with re- 
spect to their opinions on (1) dues; (2) freeloaders; 
(3) docket 15928; (4) bylaws; (5) CB liaison. I 
wrote my Director, GU Crossley, and sent copies to 
the then Vice- Director and to Harry Dannals, Hud- 
son Division Director, since I had a permanent QTH 
at my boyhood home in tliat area- 

My letter* in part, read: "Final item -amateur 
radio must have adequate representation in Washing- 
ton* Maybe ''lobby'' is a nasty word to some, but 
it is a recognized procedure. We desperately need 
it, both for our protection and advancement. I 
spent many years in Washington as an industrial 
representative, and I know how much the right word 
in the right ear at the right time can accomplish. 
Please have this considered/' 

I had no reply from either Harry or the V-D, at 
that time W3KT, but I received a very nice note 
from Gil, which read, in part: "Relative to repre- 
sentation in Washington -that is very well taken 
care of, with amateurs in the different departments 
of the government and legislative halls. What I am 
saying is not generally taken by many amateurs 
but things can^t happen without our knowing it at 
once. I certainly felt the same before I was on the 
Board, For example. Bob Booth our legal advisor 
is president of the legal organization that practices 
before the FCC- To have a so-called lobby, it would 
have to be registered and we would likely lose our 
tax exempt statis." (Sic) 

Now, it seems to me that he simply does not un- 
derstand what a lobbyist does, in the sense of the 
scope of the job beyond collection of information. 
So, I wonder if the other Directors may not like- 
wise lack that understanding? If so, how can the 
question possibly receive adequate consideration? 



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FOR TUBES 

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COMMUNICATIONS 

924 Elm St., Racine, Wis, 53403 



CONVENTION 69 
ARRL NATIONAL 

Des Moines, towa 

June 20, 21, 22 

P.O. Bex 1051, 50311 



MAY 1969 



133 



5 



p 
ft 



Also, I thought that the lax-cxemption matter 
might be of interest to you. In any event. I don't 
recall that 'lobbying/^ in any context, was consid- 
ered at the subsequent Board of Directors meetini^, 

Al Smith. W2AFJ/K3ZMS 
Doylestown, Pennsylvania 

Like you say, the rush to Extra Class doesn't 
seem to have materialized; lliis is going to crov^d 
hell out of the segments assigned to General Class. 
I have talked witli holders of Extra Class tickets 
and they tell me that most, if not all, their cronies 
are General Class; therefore, they will be using the 
upper segments in order to chat with Iht^rn* This is 
going to give our friend. Chop Chop, a chance to 
say the Extra Class segments are not being utilized 
to any great extent, so. like 1 1 meters, we may ex- 
pect to lose that portion of the band to other ser- 
vices. Those Extra Class tickets should have been 
allowed to use a part of the CW portion for phone. 
Then, maybe there would have been a bit more 
incentive, nicht wahr? 

Bert Berthelsen, W510I 
Ormond Beach^ Florida 

1 appreciate the IB job on your Advanced theory 
articles- and now the Extra. Many inx! 

Guys older in years (but not old timers m Ham 
Radio) such as myself, need this stuff interpreted 
and written as you are doing. 

Bill, WASAME 
(Now Advanced Class!) 

73 is excellent, no rubbishy padding (i.e., DX 
reports). Please keep up the good work! Over in 
the U.K., we find it very difficult to find practicai 
articles on the advanced semi-conductor devices, 
i.e., LC/s and FETs etc., so your really great arti- 
cles are appreciated. A couple of years ago, I sub- 
scribed to QST, but in one full year, I personally 
found only one article (on Ferrite Toroids) of real 
value, and needless to say, you had already covered 
them (and better) six months earlier!! Yes! 1 guess 

I'm sold on 73. 

73 and all the best for 1969. 

Chas, 93RIMV 

Cheshire^ England 

I first went on the air with the call 2-KJ in 
Brooklyn^ N-Y.-, in 1919, and have been on and off 
ever since- In almost fifty-years of ham activity, I 
have never encountered a situation such as now ex- 
ists in Phoenix, Ariz.ona, on the twenty meter band, 
approximately 14,340 MHz. 

Time after time, I have heard K7GRU come on 
and create what appears to be deliberate interfer- 
ence- Very often lie interferes with the operation 
of the Coast Guard Net trying to run overseas wel- 
fare traffic; he indulges in invective and name cal- 
ling. He settles down on QSO's in progress and 
talks of his technical excellence and the efficiency 
of his equipment yet his signal is often ten kHz 
wide. There is more but this is enough to give you 
my thoughts on the matter, tf anyone ever tried to 
give amateur radio a bad name, it is he, 

A. R.Taylor, WA 5 WM J 
Gravette, Arkansas 

^ Every project that I have built from '*73'' Mag- 
azine has worked the first time. Can*t say the same 
for any other magazine- The best one of all was 
"A Beginner's Receiver," 73 June 1963. 

I would also like to see a BC-454 or BC-455 con- 
version to 14 Mil? to 17 MHz or 15 MHz to 18 



134 



MHz. Maybe some reader would forward liis con- 
version to me? 

1 believe you have the best mii^aztnc no in*:. 
Maybe Playboy is belter, but they don't have luo 
many radio articles. 

Dick Heydt 

P.O. Box 222 

East Granby, Conn. 06026 

Just a word of appreciation for the series on the 
Advanced Class. Recently a Jiiend of mine called 
to say that he was going to Kansas City in about a 
week to try for the Extra license and suggested that 
1 go along and try for the Advanced, 1 did an inten- 
sive study using the series from 73 and passed with 
few errors. The scries was interesting, (unusual for 
such a technical subject) well- written, and very 
practical- I am looking forward to the Extra Class 
series. 

Horton Presley, K0HVK 
Ottawa^ Kansas 

73 came in late this month and I miss the letters 
from your readers, 

1 believe your graphs showing the negative re- 
sults of incentive licensing only proves my conten- 
tion that the majority of US amateurs do not ap- 
prove of this and are not going to support it. They 
feel as 1 do, the only way now to defeat it is to ig- 
nore it and the FCC will in the near future rescind 
it. 

They know it was instigated by a small selfish 
group that had undue influence witli the ICC 
through tiie ARRL for the express purpose of 
giving themselves an advantage of QRM free opera- 
ting frequencies. 

The vast majority of amateurs that have careful- 
ly thought this issue out know that passing the ad- 
vanced and extra class exams will not accomplish 
any better operating practices or will it clean up 
the violations being practiced on our bands. So it 
has no useful purpose. 

You have the wrong attitude Wayne. Laws can 
be changed -remember prohibition? 

The FCC said they would review the problem 
after it had been in use and would if the frequen- 
cies were not used sufficiently rescind it. Certainly 
only 6000 amateurs out of a quarter of a million 
does not constitute a sufficient number to justify 
any special frequencies assigned to them. So the 
majority of amateurs have in my opinion decided 
this was unjustly forced upon them and that the on- 
ly way now to defeat it is to resign from the ARRL 
and refuse to take tlie new tests in protest and to 
hope the FCC will see the mistake they have made. 

The FCC has unfairly discriminated apinst the 
CW operator. They now make him lake tlic most 
complex theory tests (both Advanced and Extra) 
when he is using the simplest of equipment, just to 
get the full use of the CW frequencies he is or was 
assigned. 1 am a CW man. 

This irresponsible action of the ARRL has ac- 
complished only one thing and that is it has em- 
phasized to the commercial interests and to the 
forthcoming convention of frequency allocations 
that the amateur bands are too large and that the 
amateur can afford to lose some of his t^equencies 
because tlie ARRL feels the great majority of ama- 
teurs can be forced into a much smaller segment of 
the bands that we now hold. This is the interpre- 
tation the commercial interests will give to this and 
use it against the amateur frequency assignments. 

I was a member of the ARRl hack in the early 

73 MAGAZINE 




w 




20's and I knew Percy Maxim personally and I sure 
liked the old man. He would not have approved 
this action of the ARRL. 

The ARRL knew they had made a mistake after 
they made this proposal but they were not big en- 
ough to admit it and went along with the hope tlie 
FCC would have the good sense not to approve it. 
This was proved by the futile way they have tried 
to justify and defend it even saying they did it just 
to create a controversy. Mow insane has an organiz- 
ation to become before it is committed? They 
don't have to be, they have committed suicide by 
themselves- "Give a fool enough rope, etc." 

Wayne, for your inform a tion> this incentive li- 
censing has done much harm in many ways, I 
would like to mention a few instances that have 
come to my attention. I have a local friend that 
has been a ham for many^ many years; he is sixty 
years old and has been very active in the past in the 
local radio club, on the T VI committee, etc., and has 
given many hours of code and theory classes and 
has many loca] hams that owe him for their tickets. 
He has always been a general and is a retired dentist. 
Well, he went to Miami and look the Extra exam. 
He passed the CW but failed the theory. This was 
very embarrassing to him and he has given up com- 
pletely-! never hear him on the air anymore and he 
gave me four big boxes of parts and equipment- the 
contents of his junk box. You see, the ARRL has 
caused us to lose a very fine amateur. This is just 
one case i know about, there must be thousands of 
others that have just given up because of this irres- 
ponsible act of the ARRL and tlie FCC. In the in- 
terest of amateur radio, I think you should still 
fight for the rescinding of this provision that has 
been forced on us- 

One of your arguments can be that amateur 
radio is truly woild-wide and international and that 
it is unfair to the USA amateurs to be restricted by 
special examination from use of parts of the bancls 
that other countries do not restrict* Amateur radio 
is international and the rules should be internation- 
al—this is only fair play. 

For example, this has brought about another 
problem that of reciprocal licensing. We have here 
in South Florida a lot of retired Canadian hams 
that live here permanently but because they are 
Canadians, have their VE calls and the Ft. Lauder- 
dale, Fla., USA, address in the Canadian call book. 
Now, with this incentive been sing that they do not 
have in Canada they do not know what parts of the 
bands they can use legally in the US, VE3CI/W4 
Heith Love talked with me about this situation the 

other day; it affects him. So you see, this unneces- 
sary act is causing many problems that did not exist 
before and have no need to exist now— it should be 
rescinded* 

Needless to say, I am no longer a member of the 
ARRL. An organization that uill fully disrespects 
the majority of its membership is not a democratic 
organiMtion* 

Many of those 6000 Extra Class are old timers 
that grandfathered in and have not been on the air 
for many years; we have several locally. 

Wayne, I wonder what has happened to the old 
steam in you -why has the fire gone out? Have you 
given up and joined the opposition? God help us! 

George Taylor, W4PZS 

1133 S,W, Fifth Place 

Fort Lauderdale, Florida 

In reference to your de W2NSD/1 editorial in 
the January issue, you should have a divorce vie- 




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tim's net. I don't think you would have any trouble 
in getting divorced people to talk. The QSO would 
start: **Let nie tell you about my case- it's differ- 
ent/^ This type of QSO would last for hours and 
far into the morning. 

Your mention of missionaries on the ham bands 
recalls to mind the fact that the Seventh-day Adven- 
tists (who were the cause of my troubles) did have 
and probably still do have, Bible networks. I used 
to get a kick out of listening to some unsuspecting 
ham joining the round table, and then getting the 
drift of what was going on-puUing out but fast* 
A psychiatrist once said that most marriages 
were dulL 1 would challenge his statement and say 
that most successful marriages are comfortabte. 
Marriages that are exciting quite often become tire- 
some and don't last too long- 
So, perhaps QSO's are not so dull but comforta- 
ble and most hams like it that way. 

George Partis, W6GHV 

Founder & Executive Director 

United States Divorce Reform, Inc. 

Kenwood, California 95452 

Each article published brings quite a mail bag 
from interested hams seeking further information or 
confirmation, not aU of whom think to include an 
SASE (or even postage)- The 4-BTV evaluation ar- 
ticle netted me 22 such letters, mostly from people 
wanting to know if I really meant the antenna was 
that good (one old timer in Iowa asked bluntly, 
"What am I suppo.scd to do with all that goddam 
wire/'— he got a polite reply and a sketch of a pro- 
posed layout of the radials for his small lot. The 
Gentrac* article has kept my mailbox busy-one 
from a missionary radio technician in the Amazon 
jungle who was attempting to build a Gentrac for 
his work and needed some advice. 

Peter Lovelock, W6AJZ 
Santa Monica^ California 

I would like to introduce a new and different 
net-The Handicappers Information Net. This net is 
now meeting Mondays, Wednesdays, and Fridays 
from^ 2000 to 2100 GMT on 7270 kHz, Although 
this is primarily a net for handicapped persons, all 
amateurs are invited to participate- Our goals are to 
aid handicapped persons in their daily personal pro- 
blems, to help handicapped amateurs advance their 
class of license, and to interest and assist other han- 
dicapped people in obtaining an amateur license. 

To make a success of our goals we need the help 
of many amateurs. Volunteers are needed to help 
set up stations for newly licensed handicapped ama- 
teurs and to give advice and encouragement to those 
studying for their licenses. Many members have 
donated various pieces of equipment while others 
have offered the loan of equipment for use by han- 
dicapped members. 

At the present time we are helping three future 
members obtain their Novice licenses- In order to 
help more we need your help. For further informa- 
tion, check into the net or contact Otto Huggins, 
WA5TIK, Assistant Net Manager, L. E. "Gib" Gib- 
bins, W5PCN, Equipment Co-ordinator, Sandy 
McDowell, W5QZY, or me. 

This is a chance to give to others the pleasure of 
ham radio that you now enjoy and of having the 
personal satisfaction of knowing you have helped 
others. 

Kathleen Wilson, WA5QQR 

Net Manager 
Handicappers Information Net 



136 



73 MAGAZINE 



r 



In your interesting aiticle on Tesla you mention- 
ed some references. Where? What did you do with 
them? 

Owen Thom(^on, WA4NXA 

I never thought you*d ask.,. here they are„.ed. 

Prodigal Genius: The Life of Nikola Tesla, John J- 
O'Neill, Ives Washburn, Inc. 1944, 

Experiments with Alternate Currents of Higli Po- 
tential and High Frequency, Nikola Tesla, 
McGraw-Hill 1904. 

Nikola Tesla: Lectures, Patents, Articles, Nikola 
Tesla Museum, Beograd, Yugoslavia 1956. 

"Tesla's Oscillator and Other Inventions," Thomas 
Commerford Martin, Century , April, 1895* 

'*The Tesla Steam Turbine: '' Scientific Americanf 
Sept. 30, 1911, 

"Nikola Tesla," Kenneth M- Swezey, Science, 16 
May, 1958. 

"My Inventions," Nikola Tesla, Electrical Exprn-i- 
menter, a series begun February, 1919. 

"Some Personal Recollections," Nikola Tesla, Scien- 
tific American, June 5^ 1915. 

"The Problem of Increasing Human Energy," Nikola 
Tesla, Century, May, 1900. 

"Nikola Tesla-Last of the Pioneers?" Leland L. 
Anderson^ Journal of Engineering Education^ 
June^ 1959, 

It has been a number of years since I have writ- 
ten to you, nevertheless, I buy 73 and read de 
W2NSD/1 your editorials beat any other Ham Ra- 
dio magazine on the market from QST to them aU. 
I particularly have enjoyed your excursion around 
differents part of the globe, especially Europe. I 
would like to call your attention to January*s issue 
on page 100, European VHP, by Lee Grimes, who is 
stationed there in Berlin. This article was one of 
the best I ever read; it was most informative. I am 
sure that there are thousands of us who enjoyed this 
article. The Editorial Liberties in the February is- 
sue brought some snickers about the ARRL request- 
ing character references from some other Hams in 
order to renew your license or obtain a Ham license. 
Your article on Nikola Tesla and his contribution to 
electronics was well appreciated ^ however, I know 
I will never have the brains to pass the Extra Class 
exam. I am satisfied with the small amount of the 
frequency band that Vm allowed to operate on* 
I agree that the incentive deal didn't change the 
picture one iota as far as I can see* 

Kenneth Mahoney, K60PG 

Reference is made to your letter of 7 February 
1969 concerning amateur radio operations from 
Navassa Island. 

Navassa Island is a small, rocky island with sheer 
sides extremely inhospitable in nature. It is unin- 
habited, lacks any source of potable water, and the 
terrain is rough and broken. The only installation 
on the island is an automated lighthouse maintained 
by the Coast Guard, A landing can only be accom- 
plished from a smaD boat and requires scaling a 40- 
foot Jacobs ladder, which is an especially hazardous 
undertaking. 

While we recognize that a well outfitted and 
organized group could reduce the hazards of visi- 
ting Navassa to some extent, we would not be able 
to supervise the operations proposed to the degree 
that would be necessary to assure the reasonable 
safetv of the individuals concerned. Since the is- 
land is under the jurisdiction of the Coast Guard, 



BACK ISSUE GUNSMOKE ! 

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and we will send you an 
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of thirty different (all 
different) back issues, 
all from the 1960-1966 
era. These are all rare 
coi lectors Items. Every 
one could Itkely be wo- 
rth a fortune to you. Who knows, you might 
even find a rare January 1961 in this pile! We 
don't even know what »s in these packages. To 
keep costs down we have had these magazines 
packed into sloppy bundles by the Chimps 
from Benson's Wild Animal Farm (nearby). 
Watch out for banana skins. —If you want 
specific fssues of 73 they are available at the 
low low (high) price of $1 each. Unless we 
don't have them, in which case the price is 
higher. —How about sending a bundle to a DX 
friend? Back issues of 73 are worth their weight 
in unicorn dung in most countries* —Money 
received without a shipping address will be used 
for beer« 

73 Magazine Peterborough NH 03458 




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MAY 1969 



137 





H 



we would retain responsibility for the safety and 
well-being of visitors in the same way as we would 
for visitors to any other Coast Guard property- 
Wit h the exception of government employees on 
official business, since 1963 it has been the judgment 
of the Coast Guard that all requests from individuals 
to visit Navassa Island should be denied. There 
have been no new developments which would 
prompt us to change our position. The reasons for 
this position are several* In addition to the dangers 
present in effecting a landing together with the com- 
plete lack of facilities or means of sustenance, the 
location remote from civilization would make any 
visitor a likely Search and Rescue case. Further- 
more, Haiti lays claim to Navassa as a Haitian de- 
pendency and refuses to recognize it as a U.S. tor* 
ritoiy. In view of this political situation a visit with 
radio equipment could easily be misinterpreted, as 
it was recently in the Middle East. 

Moreover, caU sign prefix "KC4'' that was avail- 
able for assignment to amateur stations has been de- 
leted by the FCC, and the Commission no longer 
classes Navassa as a separate country for '^DX'* 
awards* 

Therefore, the Coast Guard feels that, due to all 
of the surrounding circumstances, it is in the best 
interest of all concerned to deny individuals the 
authority to visit Navassa for any purpose save of- 
ficial buaness^ Consequently, we must deny your 
request. 

If the Coast Guard can provide any additional 
information or be of further assistance, please feel 
free to call. 

P- E- Trimble 
Vice Admiral, U.S. Coast Guard 

Acting Commandant 

(FCC is running DXCC for the ARRL now, 
I see„.,ed,) 



Lines Created on the Passing 
of Robert Evans, W3NO 

We say 73 to our dear friend, and strain to hear SK 

For W3N0 passes only to continue life, 

Perhaps not far away. 

We, here on ttiis plane, shall hear that call again. 

And know it bears another consciousness that we 

knew, 

But slill aware the old exists in us. 

For what new wavelength, frequency or harmony 

do we seek^ 

In what direction do w^e steer within the universal 

spectrum. 

To next discern that faint CQ DX? 

Do our communicators scorch to find a device, 

A demodiilalor to transform that invaricnt part of 

him. 

That we niight understand a message coming 

through? 

Wc arc beings of vibrations, constant motion, ever 

change. 

Have 3I'T and 3N0 become as One, or only part of 

us? 

*rhe answer mii^ht be found within the realm of 

transformation of ourselves. 

Amateurs have played their part in great discovery. 

There awaits uncovcry of a cosmic lixxs bj their 

probing mind- 

A few, perhaps, will make the search and answers 

find. 

Meanwhile, we really mean not to say farewell, but 

sim()ly wait for us. 



We're not far behind, 

For how now he measures time* 

S. Lee Maulsby, W3RKK 

Million Dollar Suit Progress Report 

As previously reported, the preliminary hearing 
before Judge Lieb m Federal Court in Tampa on 
Jan, 8th produced nothing concrete^ The Judge 
asked for further briefs of law from both attor- 
neys, to help him make a determination as to the 
proper disposition of the base. As a result, W4GJ0's 
attorney has filed two further brief s^ approximat- 
ing 35 pages of well-researched law. 

The opposing lawyers are asking that the case 
be remanded to Circuit Court in Sarasota County 
for trial on the ^'Nuisance/' **e!ectroni€ invasion of 
privacy" and million dollar damage charges. Our 
position is that Circuit Court has no jurisdiction 
in a matter involving a Federally granted privilege 
and responsibility. We also feel that it belongs in 
no court at this time, since the complainant fails to 
allege that he has exhausted his administrative re* 
medies before the FCC. (Although, in fact, the 
FCC Field Engineers did investigate before the suit 
was ever filed, and gave W4GJ0 a clean bill ) We 
feel that the case should be dismissed by the Feder- 
al Judtre, leavine the complainant free to take it to 
the FCC. Only if the FCC had found W4GJ0 at 
fault, and had he failed to comply with FCC orders, 
should the Federal Court be involved in enforcing 
an order of tlie FCC. This is clearly not the case* 
If the complainant feels the FCC ruling against him 
is in error, he should take it to Federal Appeals 
Court in W^ashington, D.C. We are currently aw^ait- 
ing the ruling from J udge Li eb- 

In the meantime, our case against the complain- 
ant remains in the local court. The temporary in- 
junction against the TVl complainant has been lif- 
ted, in return for sworn agreement that he will do 
nothing further to harass" W5GJ0 or his family. 
There wiU probably be further hearings in this case 
before it comes to trial. 

ARRL has provided much helpful material, hut 
they feel that they cannot participate directly or 
fmanciaiiy until and unless the case comes to trial 
in a Federal Appeals court, Mr. Bob Booth, the 
ARRL General Counsel, continues to monitor the 
case closely, and is being provided with complete 
files of the great volume of paper-work involved 
in the case- 
Good attorneys don*t come cheap, and expenses 
to date exceed S2500. Few individual hams could 
handle this, but together it should be easy to finance 
fighting our case. Thanks to 73 Magazine, Florida 
DX Report, the QCWA News and many others, 
many contributions have been received^ and need- 
less to say, they are greatly appreciated. It's impos- 
sible to estimate what total costs may be. The case 
could be dismissed soon and no appeal made, or it 
could go on into other or higher courts and drag on 
indefinitely! 

The Sarasota Amateur Radio AssociatioUj Inc., 
P. 0. Box 3323, Sarasota^ Florida 33578 has set up 
and is administering a fund to help underwrite legal 
costs in the case. Your help is urgently requested! 
Any unused funds wiU be returned to contributors 
furnishing names and addresses. 

Not only is the future of ham radio as we know 
it today at stake, but it appears that this case stiikes 
at the very power of the 1"CC to regulate! Your 
right to operate your amateur radio station without 
intimidation is involved! 



138 



73 MAGAZINE 



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and Jo Jennings, W6EI, the 
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from a simple single phase half wave choke or 
capacitor input rectifier to a three or six 
phase industrial unit. And if we don't have 
exactly what you need on hand we will build 
it. 

Diodes are available from many sources^ 
but JI is the only specialist that provides ap- 
plication engineering service to one and all..- 
amateur, experimenter, hobbyist, or commer- 
cial users. In addition to making absolutely 
sure that you are buying the unit best designed 
for your particular application, J I guarantees 
a complete curve-traced power type test on 
each and every diode sold, whether in lots of 
one or thousands, or in discrete assemblies. 
JI has some other plans afoot that may 
interest you such as a surprisingly inexpen- 



® 



sive (not cheap) line of "OZ-PAK" assem- 
blies which will be avaflable in kit form and 
capable of rectifying the full 2 kw PEP limit 
in any popular power supply configuration. 
Later we will have a series of well designed 
regulated power supplies for 6 and 12 volts 
output at 2-4 amperes and other currents. 
Heavy duty battery chargers or rectifier as- 
semblies are already available, 

JI is buying large numbers of manufactur- 
er's over-runs, end of contract excesses and 
good military and commercial surplus diodes 
and these will be available at real bargain pri- 
ces. 

JI is having special high voltage diodes 
made as well as controlled avalanche diodes 
guaranteed to meet mil specs* Three amp ax- 
ial devices soon, as well as stud devices are 

in the works. 

There is a money-back guarantee on all J I 

products! 



J6/7/?//7ffS INDUSTRIES INC. 



2730 &ituaid«t^ /toe. StuOa (gnuf. &<dcf. 95060 




4 



MAY 1969 



139 



LARGEST SELECTION in United Stat«i 
A? LOWEST PRICES — 4B hn delivery 



ThoyMndi of ffttqy«ficki in itock. 
Tvp«i include HCi/U. HCIt/U, 
R-241, FT-243, R-I7I, ifc, 
SEND Wi for catdtog wTth otcniafor 
circufti. Refund «d on fint ordtr. 

2400 B CryHAl Dr.. Ft Wyflfi, Fit MiOl 




^«ti 



^ ■- 



ipr^-' 



sra\\\5P« 



V 




These valtiable EXTRA features 
Included in both editions! 

m QSL Managers Around the 
World! 

• Census of Radio Amateurs 
throughout the worliJ! 

• Radio Amateyrs* License 
ClassI 

• World Prefix Map! 
« International Radio 

Amateur Prefixes 



GET YOUR NEW 
ISSUE NOW[ 

Over 283.000 QTHs 
in the U.S. edition 

$6.95 

Over 135.000 QTHs 

in the DX edition 

$4.95 

See your favorite deaJer or 
order direct {add 25C for 
maifing in U.S., Possessions 
S( Canada. Elsewhere add 
50«). 

Radio Amateurs' Prefixes 
by Countriesl 

AJ.RX, Phonetfc Alphabet! 

Where To Buy! 

Great Circle Bearings! 

fnternational Postal 
Information! 

Plus much more! 



BROCHUHf 



RADIO AMATEUR 



lib 



OO 



k 



INC. 



Dept 8, 925 Sherwood Drive 
Lake Blutf. Ill B0044 



PRICE WAR!! 

WE BEAT ALL AND ANY OFFERS if 

you have the equipment we want! Urgent- 
ly need any type of lab grade test equip- 
ment, and military electronics such as Gen. 
Rad., H-P, Tektronix, ARC. GRC, TED, 
PRC, VRC, ARN, URR, APN, etc. Tell 
us what you have and what you want in 
first letter! WE PAY FREIGHT! 

COLUMBIA ELECTRONICS oept. ?. 4365 w. 

Pico Blvd., Los Angeles, Cal. 90019. Phone: 
(213)938-3731. Cable: COLECTRON. 



! 




W6PHA - 
BOX 246. 



GLOBAL IMPORT CO. 
EL TORO. CALIF. 92630 



E Y<TM} 

$34.95 

Postpaid 

Electronic 
Keyer and 
Monitor 




i^ Price — $2 per 25 words for non^commerctal ads: $10 
per 25 words for business venfures. No displav ods 
or agency discount. IncJude your cheek with order* 

i^ Deadline for ods Is the 1st of tfie month two months 
prior to publication. For example: Jonuory 1st is tha 
deadline for the Mareh Issue whieli will be mailed 
on the 10th of Pebruory. 

ic Type copy. Phrase and punctuate exactly as you wtsh 
it to opptor. No all-capital ads. 

iic VVe will be the fudge of suitoblHty of ads. Qtir re« 
sponsibinty for errors extends only to printing a cor- 
rect ad in a later issue. 

lA- For $1 extro we can momtafn a reply box for you. 

# We cannot check into each odvertiser, so Caveat 
Emptor . , , 



WANTED: Schematics & Instruction Manual for 
Farnsworth Model 600A camera & control monitor* 
Contact G. D* Petrizze, 2135 N. Al!en Avenue, 
Altadena, California 91001, 

T.V. CAMERAS-Heavy Duty Industrial, Trade- 
ins, These are beefed-up babia$ that really give 
"positively the brightest, clearest picture you ever 
saw!" Complete with Schematic lens and vtdicon, 
$250. C.CT.V, Center, Inc., Route 46, Lfttle Falls, 
NJ. (201) 256*7379. 

i EXCELLENT NEW HW^32A with calibrator, man- 
uals, plus Hygain 18V; all for$125. Jim Sandberg, 
K6HE, 1138 Rustic Road, Escondido, California- 



THE OZAUKEE RADIO Club will have its annual 
hamfest at the Belgium Community Center at Bel- 
gium, Wisconsin, on May 25th, 1969- Further in- 
formation can be obtained from Ozaukee R.C., Box 
13, Port Washington, Wisconsin. 

WANTED' Very low frequency receiver (MSL-5). 
Write WA7KDZ, Box 355, Kent, Washington 98031. 

CONVERTERS, three transistor, tow noise, 50-54 
MHz in, 14-18 MHz out Adjustable frequency, 
$5.00. Solid state decade amplifiers, $35, Syntelex, 
39 Lucille, Dumont, NJ. 07628, 

3000 V @ 3/if brand new GE Pyronal oi! capacitors 
$3 each. Can mail, 3-1 bs. each shipping wt,, FOB. 
P. Wandelt, RR#1, Unadilla, New York 13849. 

"NORTHERN CALIFORNIA HAMS/' Best deals- 
new and reconditioned equipment. Write, call or 
stop for free estimate. The Wireless Shop, 1305 
Tennessee, Vallejo, Calif. 707-643-2797, 



140 



73 MAGAZINE 



F 



RTTY GEAR FOR SALE. List issued monthly, 88 
or 44 MHy torroids 5 for $1.50 postpaid. Elliott 
Buchanan & Associates, Inc, 1067 Mandana Blvd, 
Oaklahd, California 94610. 

WANTED: Military, commercral, surplus Airborni^, 
ground, transmitters, receiver, testsets accessorieis. 
Especially Collins, We pay freight and cash. Ritco 
Electronics, Box 156, Annandale, Va. Phone 703- 
560 5480 collect. 

TEST EQUIPMENT WANTED: Any equipment 
made by Hewviett-Packard, Tektronix, General Ra- 
dio, Stoddart, Measurements, Boon ton. Also mili- 
tary types With URM-I ), USM-( ), TS-{ ), SG-( ) 
and similar nomenclatures. Waveguide and coaxial 
components also needed. Please send accurate des- 
cription of what you have to sell and its condition 
to Tucker Electronics Company, Box 1 050, Garland, 
Texas 75040. 

HAMFEST, May 25th at Wabash, Indiana, 4-H fair- 
grounds, $1,00 registration, no selling charge, rain 
or shine. Information? Write K9AYB, 434 Stitt 
Street, Wabash, Indiana 46992. 

ATTENTION 160 METER FANS: Change any 
coax fed 75/80 meter inverted vee/dipole into an 
efficient 160 meter antenna. Adapts within seconds, 
right in the hamshack, PL-259 and 80-239 con< 
nectars. Perfect for residential areas. TOP BAND 
SYSTEMS' MODEL 86ADP 160 meter adaptor, 
$4.75 ppd. Martin Hartstein, 5349 Abbeyfield, 
Long Beach, California 90815. 

Swan 350, VOX, calibrator 117 xc supply spare 
finals and antenna $350, NCX-S with NCX-D sup- 
ply $200. Also two meter gear WA2NM, 212- 
428-6133. 

WANTED. Tents, Camping gear, Ampex or equal 
hi-fi stereo tape equipment, large 12ya-16'' Cassag- 
erian telescope. Pentax & Cannon Demi 35 mm 
cameras. Will buy or swap for electronic equip- 
ment such as ham gear-CCTV & Broadcast equip- 
ment listed in our new flyer 969M1— free, Denson 
Electronic Corp., P.O.Box 85, Rockville, Conn. 
06066, Telephone (203) 875-5198. 

SWAP; DAVCODR-aOwAC/DCPSSPKR, Factory 
updated and overhauled, for SBE-33 wDC PS or 
SBE'34 or transceiver. Rankin, W4ZUS, NAVEOD- 
FAC, Indian Head, Md. 20640. 



INDIANAPOLIS HAM Association ARRL Central 
Division-(SatJ May 24, Lafayette Square ( Aircon- 
ditioned) Mall, Ham & Manufacturer displays— free 
flea market or $1.00 reserved, 1000-seat cinema 
technical sessions -$1.00 family registration (Ham- 
XYL-k ids) -$2.00 at door. Banquet reservations 
$10 ea/S18 couple. Barry Goldwater (K7UGA/ 
K3VIF) guest of honor with Stu Meyers as Master 
of Ceremonies. (Pre-reservations before May 12) 
Write: Indianapolis Ham Association, 309 Benton 
Drive, Indianapolis, Indiana, 46227. 

EICO 753 Xcvr $140, homebrew, dc supply $30, 
Hustler mobile ant with 80M and 40M resonators 
with bumber mount S20, Hallicrafters S77 S.W. ra- 
dio $40, WB6LGQ, 10926 Swinton Ave., Granada 
Hills, California 91 344. 



MOTOROLA FM EQUIPMENT 
SCHEMATIC DIGEST 

91 pages { N I/2" x 17") of sche- 
ma tics, crystal information, align- 
ment instructions, service hints 
and specralfiedf information. $3.95 
post paid. 

TWO-WAY RADIO ENGINEERS, INC. 

1100 Tremont Street 
Boston, Massachusetts 02120 



RUB Command receiver, 108-1 J2 mc AM, 9 luhe, 2 uv sensitivity. No 
dial. We gjvc knob, tuning grisph^ lechnit^al data, Needs power supply 8l 
controls as oihcr Commands. NEW. .............. ^ ^ ....... . 27.50 

R21 Command receiver 540H 6Q0 kc* with knob and tutiifig graph & 

ticfuiKal data OK. , ... 17.95 

Rll A Modern O-Ver \^Q^55Q KC. 85 Kc IF. no dial. Brand new . U 2,95 
R2J/ARC-5 Command rcvr lO-5*er) 190*550 kc, has dial, w/knob & tech. 

J.;tJ OK, guiianteed. tested. ... 14.95 

SF'600-JX Receiver. 5-JO fcc lo 54 mc, in cream-puff condiiiun. . . . 125.00 
AN/ALR-5. Tunes J H- 1000 mc with ONE tunipift unit rV^25J ino4uded 
Brand new, */rcvr late type converted to 60 cy (R-444) also new or fiice 

hrjnd new, with book. ,.,...,..**.,.*... 275.00 

LM 14 (Tcq. meter J 25-20 mc» 01%* w/ier.-matched catib. ^ tecb. data. 

1 om OK ,.. , . , . 57 50 

TECHNICIANS We hire new arrivals ..B A RGAlNS...in Scopes. Counicfs. 
Signal GeneriEor^. «tc. ASK! _. 

WANTED' GOOD I AB TEST EQUIPMENT A MIL COMMUNICATIONS 

We piobabi> have thr btsi inve-niury mI' jjolkI lib le^t cquipmenl in the 
country, but please do not ask For a calaiog! Ask For specific items or 
kinds of items you need! We aUo buy! WHAT DO YOU HAVE? 



RE. GOOOHEAfIT CO inc. Box 1220 GC, BEVERLY HILLS^ CA 90213 
Phone* - trca 21 J. Office 272-57(17. Messages 275-5342. 



SURPLUS WANTED 

Equipment with Prefixes: 
ARA, ARC, ARM, ARN, APA, ASN, ASA, 
APN, APR, ARR, ASQ, GRR, GRC. GRM, 
GPM, VRC, UPX, URA, URR, URM, USM, 
UPM. SG, MD, PRM. PSM, PRC, TMQ, TRM, 
TED, SPA, SRT, CV. 

Commercial Equipment by: 
ARC, BIRD, BOONTON, BENDIX, COLLINS, 
MEASUREMENTS, HP, NARDA, GR, SPER- 

"VoVBaSH dollar paid or trade 

WE STOCK NEW HAM GEAR 

WRfTE-WIRE-PHONE 

BILL SLEP,W4FHY 

SLEP ELECTRONICS CO. 

2412 Highway 301 N., EHenton, F lar 33532 



■ 



VARIABLE CAPACITORS 

Radio Condenser Co. Four section, 40-550 mmf 
per section. For a total of 2100 mmf .010" air 

Cardwell PL-7013. Dual section, 13-260 mmf 

per section. -030'' spacing. Wt. 1 lb S2.50. 

Johnson 50QE20. Single section, 19 488 mmf 
.045" spacing, Wt, 4 lb. Reg. net $10.50 

Now only „„.,.,. ,*, ,.,...*,..*-,, ,...^3,95. 

Kingston single section. 10-245 mmf, double 

bearing, ,030" spacing. Wt. 1 lb $1.00. 

Bud MC-1855, Single section, 7-100mmfdou 
ble bearing. .024" spacing. Reg. net $2:30, 

Now only -.„.„. .,, J$ .75. 

\^hitc for free list of other variables, 

A R P QAI PQ 181 E, Wilson Bridge Road 
hKT\A^. OrtLCiO VVorthington, Ohio 43085 



^ 



MAY 1969 



141 






HAM F EST sponsored by Lancaster & Fairfield 
County ARC at Derby Downs one mile south of 
Lancaster, Ohio on BIS Road, Route 793, June 8th. 
Gigantic Swap Shop. Si. 00 registration with prizes 
every half hour. Main prize drawing. Good food at 
reasonable prices* 

WRL's used gear has trial-terms-guarantee! KWMI, 
$299,95; SR34AC. $149.95; HE45B, $79.95; Swan 
240, $179.95; Galaxy V, $229,95; B&W 5100B, 
$109.95; HX20, $149.95; HX50, S249.95; Ameco 
R5, $59.95; SX146, $189.95; HR20, $79;95; 
NC303, $1 99,95; SB301, $269.95. Hundreds more. 
Free "blue book" list. WRL, Box 919, Council 
Bluffs, Iowa 51501, 

The Augusta (Maine) Amateur Radio Club will hold 
their 10th annual Hamfest at the Calumet Club, 
route 104 Augusta on 15 June, preceeded with an 
open house and get together on Saturday evening 
the 14th at the same location. Pre-registratron, ad- 
ults $4.25; children under 12, $3,25; at the door, 
$5.00 

COLLINS ARC-2 2-9 MHz transceiver $80, Quali- 
ty. .55-42 MHz receiver Hallicrafters ARR-7, 6* 
position crystal filter, many features $80. Jerry 

Malone, W0MI i, 27 Maple, Cambridge, Mass. 021 39, 

SOMERSET COUNTY Hamfest-JuneSthXasebeer 
Church Grove, Route 219, 7 miles north of Somer- 
set, Pa. (9 a.m. -5 p,mj. Write Theodore J. Leon- 
berger, K3RCL Rd. 2, Rockwood, Pa. 15557. 

St. PETERSBURG AMATEUR Radio Club, Inc, 
will hold its annual Hamfest at Lake Maggiore Park, 
entrance ^te at 9th Street and 38th Avenue South, 



St, Petersburg, Florida, Sunday, May 18. All Hams 
and guests cordially invited. This is an old fashioned 
Hamfest with picnic lunch, swap table and prizes, 

OT^ECIAL CLOSE-OUT SALE. Rectifiers, transis- 
tors, and many other electronic parts. Lowest pri- 
ces. Send 15rf for catalog. Electronic Components 
Co,, P.O. Box 2902 S., Baton Rouge, La 

FANTASTIC- 1969 New England ARRL Conven- 
tion May 24*25, Swampcott, Massachusetts. Save 
money I Early bird registration $10.50 including 
Saturday dinner, dance and night club entertain- 
ment. Be a winner. Every major manufacturer will 
exhibit, plus top speakers from Science and Indus- 
try. Tickets: W1KC0, John McCormick, Berkeley 
Street, Taunton, Massachusetts, 

INDIANAPOLIS HAM CONVENTION. {Sat,) May 
24. (9 to 5) at beautiful Lafayette Square MalL 
I ndoor manufacturer's displays— for sale or auction. 
Free outdoor flea market, 80+ shops, cinema, for 
XYL & kids, inside airconditioned mafl. Airports & 
Interstate— H mile* Write: Indianapolis Ham Asso- 
ciation, 309 Benton Drive, Indianapolis, Ind. 46227 

3 Plastic Holders will frame and protect 60 cards, 
$1 -00-or 1 holders, $3,00. Prepaid & guaranteed. 
Patent 3309805. Tepabco Box 198N, Gallatin, 
Tennessee 37066. 

Need a Variably Capacitor for that homebrew pro- 
ject? We may have what you need at more than 
50% below regular amateur net- Send for free flyer. 
A.R,C.Sales, 181 E, Wilson Bridge Road, Worthing- 
ton, Ohio 43085. 




CHARTS AND DATA 



ON EVERY TYPE OF COAX 

KNOWN TO MAN. 



INVALUABLE (VALUABLE) BOOK 

FOR THE HAM - THE LAB 

- INDUSTRY 



SEND ORDER TO: 73 MAGAZINE 
PETERBOROUGH - N.H. - 03458 



Name- 



Address^ 



City^ 



State 



Zip 



$3.00 endosed for one 

Coax Handbook, postpaid. 



^ 



142 



73 MAGAZINE 



I 



The Atlanta Radio Club will hoFd its annual Hamfest 
on June 14 & 15 at the North DeKato Shopping 
Center, Atlanta, Georgia. This promises to be one 
of the biggest and best Hamfests ever held in Atlan- 
ta. In addition to regular Hamfest activities, we are 
aiming for the largest amount of equipment to be 
bought, traded and sold, of any Hamfest in the 
Southeastern United States, There will be plenty 
of parking spaces for trucks and station wagons, 
along with inside space for displays. Further details 
may be obtained by writing John Fearon, 3384 
Peachtree Rd., N.E., Suite 705, Atlanta, Ga. 30326. 



The East Coast VHP Society will operate station 

WA2WEB/! on 432 MHz from Mt. Equinox, Ver- 
mont on June 21 and 22, 1969. The express pur- 
pose of the expedition is to provide amateurs on the 
East Coast of the United States with the opportun- 
ity of contacting the state of Vermont on 432 MHz, 
The station will be on the air for approximately 24 
hours for scheduled and non-scheduled contacts. 
Schedules are requested from interested amateurs. 
Write; East Coast VHF Society, P.O.Box 1263, 
Paterson, NJ, Q7509. All correspondence and 
schedules will be confirmed prior to expedition. 

Regulated Power Supply Kits, ,6-4 AMP, $2.75 to 
$8.50. Zeners, thermistors, 25i, 10A Triac, $1,75, 
Diodes, 5i, Nixie, $5,00. Decimal Counter Kits, 
$3.50. Catalog. Murphy, 204 Roslyn Ave., Carle 
Place, NY. 11514. 

AUCTION-June 8th, Manchester Radio Club at 
Tower Hill, Candta, N.H^^Map and information 
S.A,S,E. W1HPM, P.CBox 661, Manchester, N,H. 

o3ioa 

How to Wrinkle a Wrinkle Finish 

When I build, I seldom strive for compact- 
ness, since I like lots of room for modifica- 
tions, pruning, and possible additional circuit- 
ry, I also like the neat appearance of rack 
mounting^ and I'm fortunate in having a free 
source of 1/8" aluminum from which to fash- 
ion panels. Finally, I have predilection for 
black wrinkle finish. Don't ask me why— I 
just dig it. 

In the past I've tried about every make of 
black wrinkle enamel in spray can I could 
find, and the results were never encouraging. 
Many of you have probably had similar ex- 
periences. It doesn't wrinkle* It doesn't dry 
for three days, and is soft enough to scratch 
with your fingernail for two or three weeks. 
At best, it looks like a sloppy job using stan- 
dard spray enamel. 

Finally, I hit on a solution. Follow the 
directions on the can: two heavy coats three 
minutes apart. Let it stand for about ten 
minutes after the second coat, and while it's 
standing, fire up the XYL's oven to 250 de- 
grees. Pop in the panel and bake it for a good 
two hours. It thoroughly stinks up the house, 
but the result is beautiful even wrinkling 
that's as hard as any professional paint job. 

Bob Grenell, W8RHR 



r 



ARC- 1 Transcftiver 100-156 Mc, 25 Wat+s AM, 

wifh tubes, schematic, conversion Info for 

2-meters. Used, qood. 50 lbs. $20.00 

ARC-t only, Fess tubes. $12,00 

BC-22I-AK with AC Power, Calib. Book & Xtal. 

$95.00 

TS*174, 20-250 Mc. Freq. Mater, on rack panel 

with AC Power, Calib, Book & Xtal. $95.00* 

Brush BL-202 2-chdnnel oscillograph, 

Used. Ekc. $90.00 

Sorensen 3000S AC Line Voltage Regulator, 

3000 V.A. Used. Exc, $125.00 

Non-Linear-Systems 451 Digital Voltmeter. P,U,R, 

Send lOc -for flyer listing surplus equipment, 

test equipment, new and used ham gear, 

JEFF-TRONICS 



4252 Pearl Rd. 



Cleveland, Ohio 44109 



WE PAY HIGHEST CASH PRICE 
for Electron Tubes & Semiconductors 

Immediate Payment on Unused Tubes 

H & L ASSOCIATES 

Eiizabethport Industrial Park 
Elizabeth, New Jersey 07206 

(201) 351 4200 



Epoxy DIODES 

1000PIV1.5A ,30 ea. $27/100 

800 PIV 1.5A .25 ea. $22/100 

Minimum Order $6 00 Postage Paid 
Money Bock Guoronfee — Write For Cost Per 1000 



Pete Fragale, W8AEN 



Box S8i 



CLARKSBURG, W.VA. 26301 



YOUR SURPLUS WANTED BY 
THi FASTEST GUN IN THE EAST 




1^. 



No horsing around, we pay fast . , in 24 
hoyfi . - . and we pay more We'll swap or 
equipmenf too We quote U^t 

ht> pay for sNippinK, insurance, etc 
You call fast; now, coDeci, lor fas! quote. 

SPACE ELECTRONICS 



noyfi . - 
^^ 4i Uade new 
ijP (00 We al 



Summit Ave. 



div, of MILITARY ELECTRONICS CORP. 
East PatwTfion. U.\. 07407, (ZOn 79I-5&50 



NO *'FREE ' CATALOGl 

Ovir new poMxy i^* to senil "FLYKllH" uiily on a fn-e hasls^: 
ami iluTt' may he no follow uji fii^ilh^ji unl^s^ >'uu orilir 
f roll I ihti JtjtT, 

W'v have a JarKt* raUlng of tU-rtronlr pafts & t^quipnu'iU 
loviT inii iiaetrii Ihal wiU b«* ^itmilted to thuj^e orderJnK 
mer SlQ.OO from th^ flytT. Catftlog depasJi is. fLQil UnUsE 

BIGELOW ELECTRONICS 

Dept. 73. P.O. Box 71. BLUFFTOM. OHIO 4Ht? 



**, j*i. 







FREE Catalog fl^'HTVi^', 

SURPLUS EieCTRONIC BARGAINS 



(A 




Now BIGGER and 
BETTER Than Evrl 

■"• MAIL THfS COUPON NOW""""— , 

NAMf' I 

_^ It ■I^T' BTl ^ |. ■.■^■■■pB^^^^flB^,,riBl|,B^li«« ■■■*■■■■■ »^I«1B11B I ■■■■■■: p « «4> p p «« 4-»l-»*«4«4 1 fB4*4 I 

I ADDRESS- ' 

1 

U - . -I 

For four f Aff ^opy* fili evf coirpoi and maf^ 0fl^#« 71 



1016 E EUREKA - Box 1105 • ilMA. OHIO 4S80? 



MAY 1969 



143 





JOHN MESHNA JR. 

19 ALLERTON. ST., LYNN, MASS. 01904 



Customer pays all shipping 

New catalog #59 now ready 

Send 250 handling & postage charge. 




PROPAGATION CHART 



TAPE PUNCH-READER-TYPER 

$7<000 Remington Synchro Tape 

machine, 8 level. Includes console 
with punch mechanism, tape reader & 
electric typewriter You type what you 
wish on (Diain copy paper, & at the 
same time, the tape punch unit in 
the console is making a duplicate on 
punched tape. You feed the punched 
tape into the reader section and out 
of the typewriter comes an exact 
duplicate of your original copy; At 
the same time you can also make 
another duplicate tape if desired. 
Make up mailing lists on punched 
tape or cards (punches tape or cards). 
You can then make original typed 
letters, etc, as many as you wish, 
with only one typing . , . the punched 
tape does the work. We offer the com 
plete machine: console with 8 level 
punch, 8 level reader, Remington 
electric typewriter. Removed in oper- 
ating condition but due to the price, 
we must sell them unchecked. Price 
includes crating. $150,00 

We also have some tape punch-read ei^ assemblies 
removed from the above equipment. Includes 
motors, tape punchy tape reader, tape transport* 
$75.00 &ach including crating. 



May, 1969 



J. H. Nelson 



syH mo** 1UFS "Ml^ THUI rli S^T 







(18 
25 



19 



20 (2^f^(2S){2^) 

euz-h (^ 29 JO J J 




Legend: Good O Fair (open) Poor □ 



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144 



73 MAGAZINE 



r 



POLY PAKS BIGGEST "ONE DOLLAR" SALE 



ON PLASTIC TRANSISTORS & INTEGRATED 



CIRCUITS 





^a^< 



i^<^^ 



-^e*' 



S9*^*^ t\»<^°^^ 



cS- 



EPOXY SILICON 
TRANSISTORS 



5 for $1 




OVER 5500,000 worth of valuable EPOXY TRAN- 
SISTORS & RTLs, OTLs. & LINEAR AMPLIFIER 
INTEGRATED CIRCUITS ... sold to you at give- 
away prices. Each and every item guaranteed or 
your money back. We include technical data, 
schematics & diagrams with all "EYE SEES". 
'^Buy now while this special limited time offering 
is going on. 



n 



Type 

2N2222 

2N2368 

2N2711 

2N2368 

2N3396 

2N3565 

2N3568 

2N3638 

2N3641-3 

2N3545 

2N3662 

2N3683 

2N3793 

2N4248 

2N4284-5 

2N4288-9 

2N4290 



910 
914 
915 
923 
925 
927 
930 
932 
933 
944 
946 
952 
953 
954 
955 
961 

^ w^ 962 

We can match up any number you desire, =; Same 



Sale 
5for$l 
5for$l 
5 for $1 
5 ford 
5 for $1 
5 for $1 
5 for $1 
S for $1 
5for$I 
5for$l 
5 for $1 
Sforjl 
5for$l 
5 for %1 
5 for $1 
5 for il 
5for$l 



Fairchild No. 



3 for $2.75 



900 
903 



Buffer 



I » -I* -I- '^m *> fwv *'* -wm 9 m- * • 



M # # **»■«* - 



brf-B + l-lll-l 



P- 4 -V 4- a b I 



400 



mc 



NPN HIGH POWER 
UHF TRANSISTORS 

D 2N3632 23W, 3A. 




3 Input Gate Nand/Nor 

Half Adder 

Dual Two Input Gate . 
Duai Two Input Gate ...,. 
Dual 3 Input Gate Nand/Nor 

JK Flip Flop 

Dual 2 Input Gate, Expander 

Quad Inverter „.., .„ 

Dual 4 Input Gate Nand/Nor 

4 Input Nand/Nor Buffer 

Dual Input Gate, Expander 

Dual 4 Input Power Gate 

Quad 2 input Gate Nand/Nor 
Dual 2 Input Inverter Gate ... 
2-2'3-lnput and Gate 
Dual 4 Input and Gate 

8 Input and Gate w/2 outputs 
Dual 4 input Gate w/expand 
Triple Gate ...... ..,,,, 

as 914 but MillUWatt type 

LOWEST PRICES ON 
LINEAR AMPLIFIERS 



Guaranteed.' With Spec. Sheets.' 3 for $6 



- •: -^ **««* ' 





D 
IJ 



Type 

702 

709 

710 

711 



Use Sale 

D.C. Amplifier $2.22 

Operational Amp 2.22 

Differential Comparator „ 2.22 

Sense Amplifier 2.22 



1 AMP TOP HAT AND EPOXIES 




1.5AMP 
2000 PIV 



*i 



PIV 

100 D 

200 D 

400 D 

«oo □ 



SALE 
.05 

.07 
.03 

.11 

.14 



PIV 

800 n 
1000 n 

1200 Q 
MOO D 
1600 D 



SALE 
.19 
,31 
.44 
.42 



PIV 
1800 □ 

2000 n 

3000 D 
4000 D 



.72 10000 D 



SALE 
.87 

1.05 
1.60 

1.90 
4.80 




1 AMP 
4000 PIV 

RECTIFIERS 




1 AMP 

MICXOMINIATURE 

SILICON RECTIFIERS 



PIV 

50 
100 
300 
400 



n 

D 



Sol* PIV SflU 

5l 600 G 30 « 

'* too U 25« 

•nooo G 3ii 



D 7. 



V 



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9 v^ 



for ■ 



COUNTING DIGITAL CIRCUIT 

D 8 Bit memory cell TO-5 case 




Terms: a<l<i pr^staj^e. Rated: net 30. cod's 25% 
Phone Orders: \V*ikefit?lir, Mass. {617} 245-3829 
Retail: :!11 AlUUm, St., Wnkufidir, Ma.ss. 

GIANT ^^SUMMIICJITALOG ON: Parts, Rectifitrs^ 
J Transistors, SCRs, LC.'s, EiErulpmentt 10^ 

P.O. BOX 942 A 
LYNNFfElD, MASS 
01 940 



POLY PAKS 



MAY 1969 



^ 



Ma 



145 



J 



■Pi 





LIBERTY 
PAYS 



MORE! 



LIBERTY 
OFFERS 



MORE! 



WILL BUY 
FOR CASH 

ALL TYPES 

ELECTRON TUBES 
SEMICONDUCTORS 
Military Eieetrenie 

Equipment 
Test Equipment 



PRESTEL FIELD STRENGTH .MEHR 

(Model 6T4G) 

Frequency Range: 40 +o 230 

A^^^^^^H and 470 to 860 Megaherh. 
'^^'^^^^^^ Calibrated outword from 10 
hf — IBSIHL **^ 50,000 Microvolts, Nothing 
IflL^JBHt "^"^^p makes It easier to properly and 

li "^ "^ speedily find the correct place 

to install TV, FM and Com- 

muntcdtion Antennas, You can 

measure and hear the signals 

with this 4^2 volt battery economically powered 

unit. There is nothing else like Itl 

Only $120.00 






WIRE, WRITE. PHONE COLLECT! WE PAY FREIGHT ON ALL PURCHASES WE MAKE 



Liberty Electronics, Inc. 

548 Broadway, New York, New York 10012, Phone 212-925-6000 



INDEX TO ADVERTISERS 



Adirondack 115 
Aerotron Ameco 41 

Amateur Wholesaie Electronics 15 
Amidon 59 

Antenna Mart 115 
Antennas (nc. 91 
A R C 141 
ARRL 133 
Arrow Sales 136 
Arcturus 135 
ATV Research 117 

BfieF 135 
Bigelow 143 
Bobs Amateur 115 
Bob Frank 136 

Brownville 121 
Brigar 1 17 
Burghardt 105 

CaMbook 105, 140 

Camp Butler 59 
Cleveland Inst. 19 
Co Ax Handbook 142 
Columbia 140 
Cubex 127 

Denson 119 
Denver Crystals 67 
Drake !V 13, 23 
Dura Towers 125 
Dymond 85 
DX Hand Book 12 

EISCO 69 
Epsilon 45 
Estes 73 
Evans 54 



Fair Radio 143 
Fragale 143 
Freck 107 

Gateway 109 
G 8i G 1 36 
Galaxy II 
Gam 73 
Global 140 
Goodheart 141 

Haf Strom 61 
Hatry 119 
H & L 143 
HCJ 109 
Henry 25 
Heights 29 

International Crystal 3 

James Research 34, 69 
JAN Crystals 140 
Jeff-tronics 143 
Jennings 139 



Lattin 93 
Lewispaul 133 
Liberty 146 

Meshna 1 44 
Mostey 35 
Murch 1 13 

National Radio 7 

Paxrtronix 65 
Pickering 1 19 



PJ/s99 
Poly Paks 145 
Productos Joga 107 

Radio Shack 31 

Redline 65, 76, 99, 111, 126 

Rohn 39 

Salch 73 
Sams 55 
Signal One 9 
Skylane 73 
Slep 141 
Space 143 
Spectrum 1 09 
Stellar 69 
Swan 7 

Telrex 99 
Tower 1 33 
Two-Way 141 

UnadiHa 97 
United Radio 137 

Vanguard 93, 103, 107, 121 
VHF Associates 121 
Vibroptex 6 

Western Electronic 136 
WRL III 

World QSL Bureau 127 

73 Magazine 
Club Finagie 1 13 
Subscriptions 125 
Gunsmoke 137 



146 



73 MAGAZINE 



ONLY WRL MAKES THIS OFFER! 



I 
I 



mMlMXW or 550 



in m 



7' 



'Js 



tZ ££ 



UimG 



The Powerful New Galaxy 
GT-550 TRANSCEIX ER 

The greatest l)reak-throitKh in 1969 Transceivers 
is Galaxy Electronics '*hnt" new GT-550. 

It has all the great qualities of Galaxy engineering* 
plus a lot of great new features — yet is still a compact 
IIV4 X 12% x6". 

They call it *'IIOT^ Husky and Handsome" and 
you will have to agree! The GT-550 has new Power,.* 
550 watts SSB, is engineered like a fine w^atch and is a 
real t)eant>\ Now available with a complete Hue of 
handsome matched accessories* 




"You've Heard 
about it— read about it 

HOW IRY IT - 

on a Two wee 

FREE TRIAL 

in your Home! 

-the Exciting NEW 

GT-550 

FIVE-BAND 

RAHSCa 



If you don't agree fhii is the greatest RIG 
Money can Buy— just send it back to us!''* 

H We have the great new GT-550 in stock and we're so confident 
you'll like it that we're going to let you try one.*. actually operate 
it yourself on "no risk" two- week FREE trial in your home! Write 
us for Free Two-Week Trial inf ormation. * 

H Remember, WRL gives the highest trade-in on your present 
equipment... offers an easy monthly payment plan (no finance 
company — direct w^ith us,) 

Check off your interests and mail in coupon! 



Larry Meyerson 

WOW OX 

World Radio 

Labs 




"The House the 
HAMSBuiltr 



I 



WORLD RADIO LABORATORIES Dept. 73-8841 

3415 West Broadway, Council Bluffs, lowc Zip 51501 I 

Please send me the following: (F.O.B. Council Bluffs^ Iowa) 
D Information on GT-550 2- Week Trial D Quote me a trade 



D FreeGalaxv GT-550 Brochure 
n Free 1969 WRL Catalog 
D Galaxy GT-550 Transceiver ($475) 
D SC5.50 Speaker Console ($19,95) 
D AC4()0 Supply {S89.95) 

Name . 



D Enclosed is 

Money Order 
D Check 
D Charge it 



Call 



Address 
Citv 



I 

I 
I 

I 
I 
I 



State 



Zip. 



■M 



NEW 



DRAKE 
MODEL 




6-M SIDEBAND 




Vfi 



♦ A*!***^'*'** 



Model TR-6 



Amateur Net 



COMPARE THESE FEATURES 

• Full coverage of 6 meter band plus MARS, 

* Four IF band widths: 2 4 kHz upper sideband (supplied), 
2.4 kHz lower sideband, 6.0 kHz AM, 0.3 kHz CW, all select- 
able with front panel switch. 

* Function switch selects product or envelope detector as 
well as built-in AM screen modulator. Compatible with linear 
amplifiers, 

• No carrier balance or carrier insertion adjustment for AM 
orCW 

* Shift carrier CW system for compatibility and versatility. 

* Ultra-stable linear VFO, 600 kHz in one range. 1 kc read* 
ability. 

• Built in PTT, VOX, ANH-VOX, 100 kHz calibrator. 

• ALC prevents ftat-topping, 

• Ample metering provisions with two meters. For ALC, S- 
Meter, Transmitter Plate Current, Relative RF Output, 

• RV6 External VFO allows split-frequency operation. (RV3, 
RV4 usable). 

• Fast or slow AGO for receiving. For meteor scatter work, 
selectable from front panel. 

• Ultimate receiver front end performance using FET's, Less 
than 1 /10|iV required for 10 dB S/N ratio on SSB. 

* Input and outputs provided for Drake TC-2 or other Z-meter 
transverters. All switching done internally with band switch. 

* 300 watts CW and PEP input, 

* 6JB6 final tubes eliminate replacement problems. 

* Extra input and output iacks for converters and /or out^ 
board receivers. Permits monitoring of more than one fre- 
quency simultaneously. 



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«Mk 



Ptug-in noise blanker accessory: $95.00 

See your distributor or write for free brochure: 

R. L. DRAKE COMPANY 

Dept 349, 540 Richard St., Miamisburg, Ohio 45342 




Exclusiue Featutes 
Greatest ¥alue 
Unmatched PeHbrman^ 

GENERAL SPECIFICATIONS 

SIZE: 5J</' high, 10^:1" wide. 16%^ deep (plus 
feet and knobs). WEIGHT: isk lbs, 
FREQUENaY COVERAGE: 49.4 to 54.0 MHz (crys- 
tals supplied for 49.9 to 5L1 only), 

VFQ DIAL CAUSRATIOK: 1 kHz divisions; dill 
accuracy is within ±1 kHz, 

CALIBRATOR; 100 kHz calibrator built in. 

FREQUENCY STABILITY: Less than 100 Hz over- 
all drift per hour after 15 minutes warm-up; less 
than 100 Hz for lo% supply voltage change. 

SPLIT FREQUENCY OPERATION: Xmt and Rev fre- 
quencies may be separated by up to 800 kHi by 
use of the RV-6 or FF-1 accessories. 
MOOES: SSB. AM, and CW, 

POWER SUPPLIES! Drake AC-3, AC 4, DC-3, DC 4 
or DC-24. 

TUBES AND SEMICONDUCTORS; 19 tubes, 7 bi- 
potar and 3 field effect transistors, 12 diodes. 

RECEIVER SPECIFICATIONS 

SENSJTIVITY: Less than 1/10 microvolt for 10 db 
S + N/N ratio at 2.4 kHz tiand width, 

SELECTIVITY: 6 dB bandwidth 2.4 kHz with USB 
filter provided. Accessory inters available for 
LSe. AM (6 kHz) and CW {.3 kHz). 

AUDIO RESPONSE: 400 to 2300 Hz at 6 dB, 
INPUT: 50 ehms unbalanced. 
OUTPUT; 4 ohms to speaker or headphones. 
AUDIO OUTPUT POWER: 2 watts at 10% HD, 

AVC: Output variation less than 3 dB for 60 dB 
input change. Fast attack. Release time select- 
able. 

MANUAL GAIN CONTROLS: RF gain control sets 
threshold for AVC, AF gain control, 

DETECTORS: Switch on front panel. Product de- 
tector for SSB and CW Envelope detector for AM. 

NOISE BLANKER: On-off switch for accessory 
Fiorse blanker on front panel. 
INPUT: 13.9 to 14.5 MHz receiving input/output 
iack for converters and/or outboard IF receivers* 

TRANSMITTER SPECIFICATIONS 

POWER INPUT; 300 W PEP on SSB. 300 W PEP on 
AM. 300 W CW (50% maximum duty cycle), 

OUTPUT IMPEDANCE: 50 ohms nom. unbalanced, 
2:1 max. SWR, Adjustable loading. 
MODES: SSB (USB provided, LSB with accessory 
filter), AM {controfled carrier system), CW {semi- 
break in, Sidetone). 

AMPLIFIED AOC; Prevents ftat-topping. 
CARRIER INSERTION AND SHIFT: Automatic on 
AM and CW, shifted carrier CW system. 

VOX ANO PTT; VOX and Anti-VOX built-in. 

AUDIO RESPONSE; 400 tO 2800 Hz at 6 dB. 

40 dS SIDEBAND SUPPRESSION above 1 KHz, 50 
dB carrier suppression. 

DISTORTION PRODUCTS: Down 30 dB minimum 
from PEP leveL 

I^ONtTDRING AND METERING: Final plate current. 
AGC action, and relative output can be read on 
meters. Sidetone for keyed CW. 

14 MHz OUTPUT; 13.9 to 14,5 MHz output for 
Drake TC-2 and other transverters. 



TR-6 ACCESSORIES 

RV6 Remote VFO. Sep- 
arates receive and 
transmit frequencies 
within the same range 

$93:35 




FF1 Fixed frequency adaptor , , , . . 

MMK-3 Mobile mounting kit 

Power supplies 

AC-4 120 V 50/50 Hz ....... .. 

DC '4 12 VDC 

MS-4 Matching speaker . * . 



» H * * 



...,$24.50 

-•..$39.95 
.,,$125,00 
.,.$210,00 

....$13.95 



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